Multi-axis joystick and transducer means therefore

ABSTRACT

The invention relates to improved multi-axis joysticks and associated multi-axis optical displacement measurement means. The joystick may comprise elements movable with respect to each other in at least, e.g., three degrees of freedom and comprise ionically conductive elements that are utilized to generate a position signal in, e.g., at least three, or at least six degrees of freedom. Various ergonomic configurations of six axis joystick embodiments which may be facilitated by the compact design of the transducer means are disclosed. Means for dynamically adjusting coordinate transformations for construction machinery control are also disclosed.

This application is a continuation application of U.S. application Ser.No. 10/511,110, filed Oct. 12, 2004, which is a National StageApplication of International Application No. PCT/US03/11614, filed Apr.14, 2003, and published on Oct. 23, 2003 as WO 03/088204 A1, saidinternational application claiming the benefit of, and filed during thependency of, U.S. Provisional Application No. 60/372,216, filed Apr. 12,2002, each said application hereby incorporated by reference.

I. TECHNICAL FIELD

The present invention relates to multi-axis input devices such asjoysticks for use in, but not limited to, control of computers, controlof computer graphics applications in the field of computer-aided design,computer games, and for control of machines such as constructionequipment, robotic manipulators, vehicles and the like. The multi-axisoptical position transducer herein disclosed may have many otherapplications, particularly where small size or low cost is important.

II. BACKGROUND

Various attempts have been made to develop commercially viable six axisjoysticks. The complexity of the prior art designs has resulted inexpensive products which may be only affordable for computer aideddesign and other high value industrial and commercial applications. The“SpaceOrb ®”, which was developed by Spacetec IMC Corporation andmarketed as a computer gaming peripheral device for several years duringthe late 1990's, was ultimately discontinued, perhaps due to itscomplexity and manufacturing cost relative to its roughly $50 to $100retail price. Patents related to the Spacetec SpaceOrb® which wereassigned to Spacetec IMC Corporation as of date of issue include U.S.Pat. No. 5,591,924 to Hilton, U.S. Pat. No. 5,706,027 to Hilton et al,and U.S. Pat. No. 5,798,748 to Hilton et al. Hilton was also granted anearlier patent in the same field, U.S. Pat. No. 4,811,608, assigned asof date of issue to Spatial Systems Pty Limited. The six axis devicescurrently offered by Logitech (which may have purchased Spacetec IMCCorp) include the Spaceball® and Spacemouse®, the January 2002 retailprices of which were approximately $500 each.

Other attempts have been made to use optical position transducers in asix-axis device. For example, U.S. Pat. App. No. 20010038380 toSalcudean et al discloses the use of light sources and sensors mountedto both the stationary and movable elements of a joystick. Such a schememay entail unnecessary complexity of construction and may result in aless reliable and less robust device due to the requirement for movableelectrical components requiring flexible connections.

Many other methods have been utilized to achieve six axis or multi-axiscontrol. For example, multi-axis input devices have also been builtaround conventional metal foil strain gage technology and also usingwire strain gages. Such devices may essentially be force input devicesand may fail to provide the operator with any useful deflectionfeedback. The primary signals from such devices may require carefulshielding and subsequent amplification to compensate for the inherentlylow gage factor of the strain gages.

U.S. Pat. No. 4,76,524 to Jenkins and U.S. Pat. No. 5,767,840 to Selkerare examples of prior art in which the use of strain gages is disclosed.The use of such strain gages may be complicated by temperature-inducederrors and low gage factors, both of which can add to the difficulty ofsignal processing and signal shielding. Furthermore, the allowablestrain may be barely perceptible to the operator, and may result in alack of useful and desirable deflection feedback to the operator.Furthermore, the low strains may preclude the use of mechanical stops toprevent overloading the strain gages. Strain gages may be sized toinclude a factor of safety with respect to loads which may decreasetheir already poor gage factor even further. Even with a factor ofsafety, the devices using strain gages may be unsuitable forapplications such as computer games, which may often be dropped on thefloor by children.

Other six axis joystick designs of prior art utilize a plurality oflinear variable differential transformers, variable inductors, or otherlinear discrete mechanical displacement transducers. Some of thesesix-axis input devices have been based on spring centered LVDT's (linearvariable differential transformers) in a Stewart platform configuration.Such devices may be expensive and fragile in comparison to theeconomical and robust construction of a 6 axis input device built inaccordance with the present invention. The multiple mechanical joints ofthe prior art may result in a trade-off between precision and cost.

An example of a simplified device of the Stewart platform variety isdisclosed in U.S. Pat. No. 6,329,812 B1 to Sundin, wherein the importantconsideration of cost is addressed. Overall complexity may not beavoided, however, because of the need to shield radio frequencyinterference and because of interference effects between adjoininginductive springs. A further disadvantage of the Sundin design may bethat the multiple springs could result in an assembly that is subject tounacceptable resonant vibrations if used in association withconstruction equipment or moving vehicles. Such vibration may includeresonance of the active grip on its spring(s) or may involve lateral orhigher mode vibrations within the springs themselves.

Yet another known six-axis joystick may be comprised of a plurality ofmagnetic sensing coils and multiple movable magnets. Examples of patentsdisclosing magnetic position detection include U.S. Pat. App. No20010055002 to Endo and U.S. Pat. No. 5,687,080 to Hoyt et al. Thesedesigns may often be much more complex and expensive than the presentinvention and may not provide any inherent shielding from ambientmagnetic flux

Yet another method is the coupling of two three-axis controllers toattain six axes control as disclosed in U.S. Pat. Nos. 5,749,577 and6,033,309 to Couch et al. Such a method may be more expensive than thepresent invention and may lack an intuitive six-axis interface.

The large size of many of the devices built in accordance with prior artmay result in unintended and undesirable coupling between the horizontalaxis of rotation and the horizontal axis of translation. Such couplingmay require subsequent diagonalization by means of signal processingwith a corresponding loss in precision and dynamic range of the device.Such undesirable coupling may have been difficult to avoid in the priorart because of the expense and technical obstacles, which the requiredminiaturization of such prior art designs may entail.

The transducer systems of the six axis joysticks of the prior art mayhave generally been physically too large or heavy for many applicationssuch as incorporation into keyboards or hand held computers, forpositioning as extensions of other control handles or grips, or forenclosing near the center of the user's hand within a conventionaljoystick such as that disclosed in U.S. Pat. No. Des. 381,701 toSalinas.

The need for hand stabilization during trackball use while operating anaircraft has been recognized. Dassault Aviation has adapted aconventional two-axis track ball to include a palm rest to facilitatereliable (two axis) cockpit display cursor control under turbulentflight conditions (PROFESSIONAL PILOT magazine/January 2002). Six axisdevices of the prior art may be too bulky to incorporate within such apalm rest. In fact, many six axis input devices of the prior art mayhave been so bulky that they no longer resemble sticks and may havetherefore not even been referred to as “joysticks”.

Various multi-axis input devices or “joysticks” that utilize some formof magnetic field measurement such as Hall effect sensing are known.Examples of patents related to multi-axis input devices or joystickswhich disclose Hall Effect sensing include U.S. Pat. No. 5,959,863 toHoyt et al and U.S. Pat. No. 5,687,080 to Hoyt et al. U.S. Pat. App.2001/0055002 to Endo also discloses the use of Hall Effect sensing formulti-axial computer input devices.

Several articles on the subject of six axis user interfaces by ShuminZhai, Ph.D. have been published. These include: Human Performance in SixDegree of Freedom Input Control, Interaction in 3D Graphics, and UserPerformance in Relation to 3D Input Device Design.

It is an object of this invention to provide a low-cost robustalternative to current multi-axis computer input devices. In particular,an object of this invention may be to provide a device sufficiently lowin cost to be attractive for use in conjunction with computer games, andthe like, as well as sufficiently simple and robust for use in, but notlimited to, industrial applications. Currently available devices may beprohibitively high priced for the computer gaming industry and may betoo fragile for a typical construction equipment application. Thepresent invention, in contrast, may require only two moving parts, whichcan be a simple coil spring and a simple plastic knob with an internalreflective surface, for example. The plastic knob of the presentinvention may have about the same manufacturing cost as an ordinaryflashlight reflector. The overall manufacturing cost of the presentinvention may be significantly lower than the manufacturing cost of anyother prior art six-axis joystick and may be in fact lower than themanufacturing cost of typical two axis joysticks.

A further object of this invention may be to provide a simpleeasy-to-manufacture 6-axis computer input device, consisting of as fewcomponents as possible. The preferred design may incorporate all, 7 forexample, transducers onto a single printed circuit board or into amonolithic electro-optical package.

Another object of this invention may be to provide a high quality andhigh precision signal by optimally locating a high-resolution transducerelement with respect to the grip and the user's hand and wrist to yieldwell conditioned transform equations.

Yet another object of this invention may be to provide a durable, robustmulti-axis input device suitable for such applications as control ofmachinery and construction equipment, and the like.

A further object of this invention may be to allow greater control inindustrial and construction equipment applications in general, wheremulti-axis controls may have been technically deficient and commerciallyunattractive.

Another object of this invention may be to provide a transducer elementof sufficiently small size that it can be centrally located within thehandle of a gaming joystick, in line with theparallel-to-the-Ulna-and-Radius-bones axis of wrist rotation instead ofbelow said axis, as may often be the case for prior art designs.

A further object of this invention is to provide a transducer elementwhich may be of sufficiently small size to permit easy finger-tipmanipulation of the active grip, while leaving space within the user'shand for a stationary grip element or a palm rest which may be needed tostabilize the user's hand and arm so that the multi-axis joystickfunctions can be safely used in moving vehicles on land, in water, inair or in space.

III. DISCLOSURE OF THE INVENTION

Various embodiments designed to meet the forgoing objectives aresummarized as follows:

In one embodiment, the present invention may be comprised of a movable“active grip” which incorporates six or so mirror facets fixed theretoand which may be resiliently mounted on a coil spring, for example. Aphoto transducer array, comprised of one or more photo emitters and oneor more photo detectors, may be fixedly mounted a short distance awayopposite the movable mirror facet assembly. The lengths of six uniquelight paths connecting the photo emitter(s) with the photo sensor(s) byway of the mirror facets may define the coordinates in six degrees offreedom of the active grip and its mirror facets relative to the phototransducer array. The brightness as measured by a photo detector at theend of each light path may generally be an inverse square function ofthe light path length. Any translational or rotational movement aboutany axis of the active grip may result in an altered pattern ofbrightness. The brightness pattern may be converted to electronic formfor use in a digital computer, for example, or may be transmitted alongfiber optic cables as an analog brightness signal.

In general, the following descriptions of the locations of photoemitters and photo detectors may be intended as examples only and arenot intended to be limiting with respect to the disclosure of thisinvention or to the interpretation of any claims. In particular, therelative positions of photo emitters and photo detectors may be, inalmost all cases, interchangeable. In certain cases individual discretedevices may be able to function as both emitter and detector. Simplechanges in circuitry may facilitate the exchange in position of theemitters and detectors. For example, in the case of six emitterssurrounding a single detector, the emitters may be energized one at atime so the signal generated by the detector can be associated with aunique light path and its corresponding emitter. Such an arrangement canbe advantageously used to reduce to one the number of analog to digitalconversion channels required on a programmable interface controller orother signal conversion device. Such an arrangement can be accomplishedusing standard components and known electronic engineering principles.

The terms “photo emitter” and “photo detector” are intended to beinterpreted broadly and to encompass any means of or element fordirecting or converting light or any interface through which light isconveyed, whether or not the light originates or terminates within thedevice contemplated by this invention. For example, sun light could beused to illuminate a target from which point it would reflect to aplurality of movable mirrors from which it would be further reflected tolight receptors from which it might be further transmitted as lightguided by a fiber optic cable to a remote location beyond some physicalboundaries. Examples of photo emitters may include, but not be limitedto, light emitting diodes of any wavelength including visible andinfrared, laser diodes, gas discharge tubes, incandescent light bulbs,and other equivalent element known or not known at this time. Examplesof detectors include photo diodes, phototransistors, Cadmium Sulfidephoto resistors, photovoltaic cells, phototubes, and other equivalentmeans known or not known at this time. The following terms as used inthe specification can be used in their traditional sense and can havethe following additional indicated meanings. The term “Stewart platform”may include a “hexapod” or octahedral parallel linkage of the typecommonly used as the motion platform for flight simulators.

The term “slave platform” may include a platform the position of whichis controlled by a plurality of remotely controlled actuators or itsvirtual equivalent in the case of manipulation of a computer model.

The term “sensing assembly” may include the assembly of one or morediscrete sensors or a single multi-axis sensing element.

The term “sensor base” may include the relatively stationary object towhich the sensing assembly is attached.

The term “sensor platform” may include the portion of the device, whichis moved by the operator including the “active grip”.

The term “active grip” may include the movable portion of the device theposition of which is moved by the operator and the movement of whichresults in a change in output signal.

The term “restoring element” may include a device such as a spring orelastomeric structure that contributes to restoring the moving platformto a minimum energy position after the removal of deflecting forces.

The term “restoring system” may include the system comprised of one ormore “restoring elements” which restore the moving platform to a minimumenergy position after the removal of deflecting forces.

The term “structured light” may include light projected in a fixed,preferably high contrast, pattern which may be used to measure as animage taken from another vantage point the position in space of anotherwise featureless surface.

The term “MEMS” refers to a class of miniature mechanical devicesmanufactured and packaged in a manner similar to that used forelectronic integrated circuit chips.

The term “CCD array” refers to an optical image sensing device based oncharge coupled devices, as are commonly used in video cameras andelectronic still cameras.

The term “side looking” as it applies to photo emitters and photodetectors refers to devices which are oriented in a circuit boardmountable package in a manner which results in emission of orsensitivity to light generally parallel to the plane of the circuitboard.

The term “joystick” may broadly include any handle, knob or other devicewhich may be physically grasped, engaged, or physically moved to in amanner which generates an electrical, optical, electromagnetic, or othersignal representation of movement of or application of forces to saiddevice.

The term “spatially varying reflectivity” may include the marginal edgesof a reflecting surface, varying specularity of surfaces, varyingreflectivity of surfaces, varying color of surfaces, transparentfeatures, opaque features, grey scale features, bar code features,printed features, prismatic elements, refractive elements, etc.

In accordance with one aspect of the invention, the active grip mayincorporate a system of optical elements such as mirrors or prisms,which control the light paths between one or more light sources and oneor more light detectors.

In accordance with a further aspect of the invention, a single photodetector may be used in conjunction with multiple switched light sourcesin order to reduce analog to digital conversion requirements to a singlechannel.

In accordance with a further aspect of the invention, in conjunctionwith multiple switched light sources, multiple photo detectors may beconnected in parallel to a fewer number, such as one, of analog inputchannels, thus reducing the required number of analog to digitalconversion channels.

In accordance with another aspect of the invention, a single monolithicphoto transducer package, which may be similar in construction to aseven segment LED package, may function as either one of or both of bothphoto emitter and photo detection elements.

In accordance with a further object of this invention, six infraredlight emitting diodes and one or more photo diodes may be mounted to aprinted circuit board to which transparent waveguides are subsequentlymolded and over which an opaque material may be molded, thus creating acompact and robust electro-optical package.

In accordance with a further object of this invention, the infraredlight emitting diodes and photo diodes may be coplanarly mounted to theprinted circuit board and the waveguides may incorporate internalreflective surfaces which project the light in a generally radialdirection from the transducer axis of symmetry.

In accordance with a further aspect of the invention, a signalprocessing chip, such as an Analog Device's PIC, may be embedded alongwith the optical transducers within the transducer package. By thismeans, any required sequencing of photo emitters, scaling andnormalization of data, as well as efficient digital transmission of theoutput signal may be accomplished within an ergonomically adaptable andcompact device.

In accordance with a further aspect of the invention, an image detectorsuch as a CCD array may be used to measure the position of an imagecontrolled by the multi-axis position of a movable grip.

In accordance with a further aspect of this invention, a very wide anglelens such the type used to preview visitors through doors may be used toproject the position sensitive image of an interior surface of a movablegrip onto an image transducer such as a conventional CCD array.

In accordance with a further aspect of this invention, the interior of amovable grip may feature a pattern of reflective areas andnon-reflective areas in a generally three lobed form.

In accordance with a further aspect of the invention, a CCD arrayattached to a first movable portion of a joystick, the base for example,may be used to measure the spherical angles to three points, for exampleon a second movable portion of said joystick, the interior of the grip,for example. The two spherical angles for each of three relativelymovable points constitute 6 data signals which may be relatively easilyprocessed by the general method disclosed herein, for example. Inaccordance with a further aspect of this invention, illumination of afirst movable portion may be by means of a photo emitter fixed to asecond movable portion located coaxially with a lens means used to focusa position sensitive image onto a CCD array.

In accordance with a further aspect of this invention, the interior of amovable grip may feature a pattern of reflective areas andnon-reflective areas in a generally multi-lobed form.

In accordance with a further aspect of the invention, structuredpatterns of light may be projected from a first element onto a secondelement, movable in multiple axes relative to the first element. Theresulting patterns of illumination may be used to determine the relativemulti-axial positions of said first and second elements by means ofdetectors or imaging apparatus attached to the first element, forexample. Such an arrangement may be used to determine the relativeposition of a reflective second element without the requirement for asecond element surface of spatially varying reflectivity.

In accordance with a further aspect of the invention, a monolithic phototransducer package as herein described may include an element to secureone or more springs.

In accordance with a further aspect of the invention, photo emitters andphoto detectors, which may be more cheaply available with integralcollimating lenses, may be embedded in an opaque insulating compoundwhile held in position, by being fixed to a printed circuit board forexample, then may be subsequently machined or sanded as an assembly tocreate a suitable optical surface.

In accordance with a further aspect of the invention, alternating sidelooking emitters and side looking photo diodes may be located facingoutward around the periphery of a printed circuit board, said circuitboard being mounted to the first of at least two movable elements(preferably the base). The second element (preferably the grip), movablein multiple axes relative to the first element, includes reflectingmeans which generally surrounds the first element at a distancesufficient to allow necessary radial movements. The reflecting means maybe a patterned surface of cylindrical, spherical, or toroidal form forexample.

In accordance with a further aspect of the invention, the photodetectors may be connected in parallel.

In accordance with a further aspect of the invention, the reflectingmeans may be a generally cylindrical mirror with spatially varyingreflectivity.

In accordance with a further aspect of the invention, the reflectingmeans may be a generally toroidal mirror with spatially varyingreflectivity.

In accordance with a further aspect of the invention, the reflectingmeans may be retroreflective, e.g., a plurality of conical reflectingsurfaces.

In accordance with a further aspect of the invention, the reflectingmeans may be polygonal.

In accordance with a further aspect of the invention, the reflectivemeans may be generally spherical.

In accordance with a further aspect of this invention, a singlegenerally planar spring may be used to provide a restoring force to themovable grip.

In accordance with a further aspect of this invention, said generallyplanar spring may be provided with positive locating features such asholes to control the alignment between the grip and the base duringassembly.

In accordance with a further aspect of this invention, a generallyplanar bellows means may be provided in conjunction with said generallyplanar spring.

In accordance with a further aspect of this invention, a non-circularhole in the grip may engage a non-circular transducer supportingpedestal in order to limit the extent of movement of the grip relativeto the base.

In accordance with a further aspect of this invention, said non-circularhole is a slot with generally parallel sides and the pedestal is ofsimilar but smaller cross section.

In accordance with a further aspect of the invention, a suitablereflector element may be provided to facilitate the use of a standardLED display package, such as a 7 segment LED numeric display for lightemission and/or light detection means.

In accordance with another aspect of the invention, optical guides maybe used to alter the effective geometric locations of a standardmulti-segment LED to a more optimum motion transducer configuration suchas a six-sided isometric array.

In accordance with another aspect of the invention, refractive elementor lens means such as inclined surfaces or Fresnel lenses may beintegral with or disposed above the light transducer array.

In accordance with another aspect of the invention, the movablereflective element may be comprised of non-flat reflecting segments suchas concave mirrored surfaces, for example, in order to obtain thedesired response characteristics from the device.

In accordance with another aspect of the invention, the movablereflector means may be comprised of one or more retro-reflectors, themovement of which may alter the degree of coupling between one or morephoto emitters and one or more photo detectors.

In accordance with a further aspect of the invention, the degree ofcoupling of emitter/detector pairs may increase with distance to acorresponding retro-reflector due to an increase in the degree ofoverlap of the respective cones of brightness and sensitivity withincreased distance.

In accordance with another aspect of the invention, the degree ofcoupling of adjacent emitter/detector pairs may decrease with distanceto a corresponding retro-reflector due to inverse-square distanceprinciples.

In accordance with a further aspect of the invention, surfaces, whichmay be retro-reflective along one axis, but conventionally reflectivealong another axis, may be mounted to a movable active grip in order toproduce position measurements in conjunction with a seven-transducerhexagonal array, for example.

According to a further aspect of the invention, the active grip may befitted with grooved mirror segments, analogous to a Fresnel lens, andmay be used to control the various light paths.

In accordance with another aspect of the invention, gain calibration ofthe various photo emitters and photo detectors may be achieved byinterposing between said transducers and reflecting elements acalibration mask element, the optical transmissivity of which may bemapped and scaled to provide a desirable balance of signals over theintended range of displacement and to compensate for the manufacturinginduced variations in the characteristics of each of the discretedevices.

In accordance with yet another aspect of the invention, a lens elementand calibration mask means may be combined functions of a singlecomponent.

In accordance with another aspect of the invention, an extra light pathmay be provided in order to calibrate brightness, which may change dueto voltage fluctuations, temperature changes, etc.

In accordance with another aspect of the invention, a light baffle maybe provided which may also serve to precisely locate and orient theoptical components on a printed circuit board, for example.

In accordance with yet another aspect of the invention, fiber opticguides may be used to convey light from a single source to multiple, sixfor example, projection points.

In accordance with another aspect of the invention fiber optic guidesmay be used to convey light from multiple detection points to a singlephoto detector.

In accordance with another aspect of the invention, fiber optic guidesmay be used to convey light from a single photo emitter to multipleemission points.

In accordance with a further aspect of this invention, time-of-flightcriteria may be used to measure the varying optical distances betweenthe various optical emitters and detectors of this invention. Suchtime-of-flight measurements may be made with known optical distancemeasuring circuitry and optical transducers.

In accordance with a further aspect of this invention, a unique opticaldelay line may be provided in series with each of, six, for example,light (distance measuring) paths for the purpose of time multiplexingoptical time-of-flight signals. This scheme may facilitate the use of asingle photo-detector channel and may also simultaneously facilitate theuse of a single photo-emitter.

In accordance with a further aspect of this invention, a multi-axisinterferometric position measurement device may be utilized for thepurpose of obtaining simultaneous precise multi-axis measurements. Sucha device may be constructed by the addition of a direct (not affected bysensor platform deflections) reference light path from a common,preferably coherent, light source to each of six, for example,photo-sensors.

In accordance with a further aspect of the invention, a photo-emitter,reference light paths, and photo-detectors may be all contained within amonolithic optic/electronic package.

In accordance with a further aspect of the invention, an embodiment ofthis invention may be constructed wherein light passes through a liquidor gel in its path from photo-emitter to mirror to photo-sensor. Such ascheme could be used, for example to minimize undesirable reflections orto exclude water or dirt from the optical paths.

In accordance with a further aspect of this invention, said liquid orgel may have a controlled opacity so as to enhance or change a signalwith a change in optical path length.

A further aspect of the invention may be the addition of a tare switchfunction to sense whether the device is being operated or not. Such atare switch function can be used to provide a null output and anoptional control lock signal whenever the device is not being used. Thisscheme may serve to compensate for null point drift due to factors suchas temperature change or a change in the orientation of the device withrespect to gravity. This scheme may also render harmless any tendency ofthe active grip assembly to vibrate in response to ambient mechanicalexcitation in the absence of the damping effect of the user's hand.

According to a further aspect of the invention, a tare switch functionmay be accomplished by a capacitive touch sensor element, a mechanicalswitch element, or by means of software algorithms designed to detectthe absence of hand initiated signals. Tare switches may be mounted, forexample to a palm rest, a wrist rest, or to the active grip of thedevice.

According to a further aspect of the invention, electrical connection toa tare switch element may be through one or more resilient elements as,for example, through a spring supporting the active grip.

According to a further aspect of this invention, a tare switch functionmay serve to measure the applied force due to the weight the operator'shand and forearm on a joystick, for example. In this embodiment, aninitial signal may represent forces due to weight, while a subsequentsignal could represent said weight plus intended operator inputs. A tarefunction element, which could be implemented by either hardware orsoftware, may cause the weight component to be ignored or “tared out”.The aforementioned scheme may then allow an operator to comfortably restthe weight of his or her hand and forearm on said joystick prior to thetransmission or utilization of the output signal of said joystick. Inthis manner the joystick might first function to measure the weighteffects of the user's hand and forearm, then subsequently function totransduce the intended inputs of the operator. The transition fromweighing function to transducer function could be accomplished purely bysoftware using appropriate time delays, or could be activated by variousforms of physical tare switches. For example, a general whole-gripcapacitive touch sensor could be used in conjunction with a timerfunction to allow one second, for example, for weighing of the user'shand, after which any further change in signals may be machineinterpreted as an intended operator instruction. As another example, afinger operated switch could be pressed at will by the operator to resetthe tare function to zero at any time.

Various schemes may be used to maximize the usefulness of the signalsgenerated by the device of this invention. For purposes of controllingcomputer graphics, it may be very advantageous to use software tointerpret the intent of the operator, rather than simply transformdisplacement generated signals to velocity of the object such as a solidmodel or camera view-point being manipulated. According to oneembodiment of this invention, the virtual object being controlled may beassigned a virtual mass, center of gravity location and moments ofinertia about each axis. The output signals from the device of thisinvention may then be translated to effective forces acting on saidvirtual mass. In this manner, smooth and predictable movements may beeasily obtained. According to a further aspect of this invention,proportional/integral/derivative control schemes may be used withcoefficients selected so as to most closely meet the operator's intent.

In accordance with another aspect of the invention, the origin of the x,y, and z-axis may be offset with software to be located at the naturalpivot point of the user's wrist even though the physical device mayremain at a location where it can be gripped by the user's hand orfingers.

In accordance with a further aspect of the invention, the orientationsof the x, y, and z axis may be rotated to suit the user.

In accordance with a further aspect of the invention, software may beused to override operator generated signals to prevent buckling,collisions, or other undesirable positions of a slave platform or adevice mounted to such a platform.

In accordance with another aspect of the invention, the coordinates ofthe device may be transformed to correspond with a dynamically changingcoordinate system or alternative coordinate systems. Changes incoordinate transformation may be made in real time as in following amoving machine, for example.

In accordance with another aspect of the invention, the coordinates ofthe multi-axis joystick may be transformed to control construction orlogging machinery or attachments such as blades, loader buckets, liftingforks, augers, pavement breakers, manipulators, and the like.

In accordance with a further aspect of the invention, sensors such asMEMS accelerometers and angular rate sensors may be attached to variousportions of machinery to be controlled in order to accomplish real timecoordinate transformations. In such an application, the possibly higheraccuracy of customary absolute angle and position measuring devices maynot be required and may be expensive. Such a control scheme inaccordance with this invention may be particularly attractive forconstruction equipment not originally equipped with position sensors andfor hexapod (Stewart Platform) implementations for which the total costof six absolute position sensors may be significant.

In accordance with a further aspect of this invention, a hexapod may beequipped with accelerometers or rate sensors at several locations (threefor example) on each of the base platform and the slave platform, aswell as near end of each actuator, strut, or link. With such aconfiguration sufficient information may be available to,instantaneously and without the need for integrating, measure position,velocity and acceleration.

In accordance with a further aspect of the invention, a hexapod may beused as a manipulation stage in conjunction with conventionalconstruction equipment.

In accordance with a further aspect of the invention, a hexapod may beconfigured as an extension of a standard implement adaptor, using maleand female adaptors at its respective base and slave platforms.

In accordance with a further aspect of the invention, a multi-axis,hexapod for example, equipment adaptor may be fitted with a motioncontrol module powered by a conventional single circuit hydraulic supplyor other power source. The motion control module may incorporate ahydraulically driven generator for powering servo valves, electricactuators, or other associated electronic devices. Control signals arepreferably transmitted wirelessly between a joystick such as hereindisclosed, to the adaptor, possibly through computers located at eitheror both ends of the signal transmission path. In accordance with afurther aspect of the invention, the required sensors, which may be MEMSacceleration or angular rate sensors, are connected wirelessly, by awireless network for example.

In accordance with a further aspect of this invention, sensors atdiscrete points, such as MEMS acceleration and angular rate sensors, maybe supplemented by angular position sensors, linear position sensors,and the like.

In accordance with a further aspect of the invention, machine visionbased sensing may be used separately or in conjunction with theaforementioned sensors at discrete points. Such a configuration maypermit high accuracy while eliminating the need for highly precisemechanisms and expensive absolute positions encoders. Machine visioncontrol of motion may utilize high resolution optics with limited fieldsof view within portions of the motion envelope where high local accuracyis required, in combination with lower accuracy wide angle visionequipment for coordinate transformation. Geometry for coordinatetransformation purposes may be provided by or supplemented by, theaforementioned MEMS accelerometers and angular rate sensors at discretepoints, or conventional angle and displacement sensors.

In accordance with a further aspect of the invention, machine vision maybe used to determine the posture of a controlled machine for the purposeof aligning in real time the coordinate systems of a joystick with thecoordinate system of the device being controlled.

According to a further aspect of the invention, machine vision systemsmay be used to simultaneously to provide images to the operator forremote control while also providing machine interpreted information forreal time adaptation of coordinate transformations between the joystickand controlled device. One or more machine vision systems may be used tosimultaneously provide video information to both a human operator and acoordinate transformation controller.

In accordance with another aspect of the invention, coordinatetransforms may allow control to be relative to any particular desiredpoint within the slave moving platform coordinate system or othercoordinate system such as that of a fixed work piece or an element of aconstruction project. Examples of specific points that would make usefultemporary slave platform coordinate origins may include; the tip of anauger or drill, center point between fork tips, a bolt hole pattern atthe end of a steel beam, an object being tracked or observed by acamera, an object of interest such as an area of interest within CATscan data set or computer model, and the like. Slave platform motion maybe controlled relative to any one of various “fixed” coordinate systemssuch as the portion of the equipment such as a loader or forklift towhich the multi-axis or hexapod manipulator may be attached, theoperator of the equipment, or even the fixed frame or ground on whichthe equipment is supported.

In accordance with a further aspect of the invention, machine visiondetection of the operators eye(s) may be used to allow the operator todesignate from time to time new coordinate origins, coordinateorientations, or motion constraints. Such an eye designation schememight allow the operator of a multi-axis manipulator to designate thatone end of a structural girder, for example, remain constrained whilethe other end is aligned for bolting under joystick control. This mayallow an operator to concentrate on bolt hole alignment without concernfor doing damage with the other end of the girder.

In accordance with another aspect of the invention, movement of theslave platform along selected axis may be selectively constrained. Bytemporarily constraining movement from 6 to fewer degrees of freedomusing application-specific constraints, greater accuracy and utility canbe achieved. This may be important in industrial applications such asdrilling where the alignment (tip location and drill orientation) ischosen with 5-axis or 6-axis control, after which the drill axis isfixed during drilling, or forklift operation where the fork position andalignment might be best accomplished with 6-axis control, but adirect-forward followed by a direct-upward movement is desired forlifting a load.

In accordance with a further aspect of the invention, a touch screengraphic representation of the controlled equipment or payload may beused by the operator to graphically select the origin and/or orientationof the coordinate system.

In accordance with another aspect of the invention, an operator of arobotic manipulator may be able to designate the end of a structuralbeam, for example, as an axis origin by three times placing said end ofsaid beam at the same location but with three different beam axisorientations.

According to another aspect of the invention, an operator may select theorigins of the x, y, and z axis in any of the input device coordinatesystems, the slave platform coordinate system, or computer modelcoordinate system to be offset by specified distances, i.e., to benon-intersecting and to be inclined by specified angles, i.e., notnormal.

In accordance with a further aspect of the invention, in order toaccurately calculate fixed-frame coordinates, a slave platform mountedtilt sensor may be used to directly measure 2 axes of rotation betweenthe tool and gravitational coordinates. Alternatively, slave platformmounted sensors such as laser distances gauges may be used to determinethe orientation of a flat surface for the purpose, for example, oforienting a drill bit normal to said surface.

In accordance with a further aspect of this invention, software code maybe used to compensate for any unintended coupling, due to coil springasymmetry, of the translational axis and rotational axis, which arecoaxial with a coil spring type restoring element.

Various additional embodiments of this invention that may enhance itsusefulness or contribute to its ease of use are described as follows:

One embodiment of the present invention may provide for a multi-axisjoystick, the base of which may be gripped within the palm of theoperator's hand and held by the ring finger and little finger, while theactive grip of which may be manipulated by the operator's thumb,forefinger and middle finger. Such a configuration may allow freedom ofwrist and arm movements while walking, presenting information to others,or performing construction tasks, for example.

In accordance with a further aspect of the present invention, aconventional computer mouse may serve as the base to which a six axisinput device of this invention may be mounted. In such a configuration,the base portion may be controlled by the user's hand or palm and mayserve as a conventional computer mouse providing, for example, twodegrees of freedom, while an appended multi-axis input device providesan additional six degree of freedom and may be independently controlled,for example, by means of the user's thumb, forefinger and middle finger.Such a configuration may, for example, provide 8 degrees of freedom.

In accordance with a further aspect of this invention, a computer mousemay be equipped with an additional, optical for example, transducerlocated at a point offset from the location of the conventional x and yaxis mouse movement transducers, thus providing an additional mouse axissensitive to differential movements between the offset transducers orrotational movements about a vertical axis of the mouse as a whole. Inthis manner twist movements may be used to generate an additional, orthird for example, output axis. Such a configuration may, for example,provide nine degrees of freedom. A twisting motion about a vertical axismay be more ergonomically accomplished with a mouse with a “pistol” or“gaming joystick” grip, the use of which vertically aligns the wrist endof the user's Radius and Ulna bones. The user's wrist may be rotatedapproximately 90 degrees in such an orientation compared to perhaps 30degrees when the users hand grips a conventional mouse. The “pistol” or“gaming joystick” grip has the further advantage in this embodiment thatit may also be secured against the user's palm with the little fingerand ring finger, leaving the users thumb, index finger, and middlefinger free to actuate buttons and/or an appended (small) joystick. Sucha grip may be optimized for comfortable and secure gripping using onlythe little finger and ring finger against the user's palm. The severaltransducer means of this invention may be more suitable than those ofthe prior art for construction a joystick sufficiently small foroperation using the index finger, middle finger, and thumb only andsufficiently small for attachment to a first joystick or mouse. Some ofthe prior art joystick designs which might allow a desirably large rangeof motion may be particularly difficult to miniaturize in robust form.

In accordance with a further aspect of this invention, the thumboperated transducers as described in Patent Application Publication No.US2002/0104957 A1 may be provided at several locations offset from eachother in order to provide additional degrees of freedom.

In accordance with a further aspect of this invention the three degreesof freedom associated with a three axis mouse, such as the one hereindescribed or one with a scroll wheel, might be used to provide 3 degreesof freedom for picking elements within a solid computer aided designmodel, while the attached multi-axis device might then provide anadditional 6 degrees of freedom which might be used to manipulate theelements selected by means of the first three axis.

In accordance with a further aspect of the invention, a finger and thumboperated six degree of freedom device may be mounted to a palm held sixdegree of freedom input device to provide simultaneous 12 axis controlwith only one hand. Such a combination might be used for example tocontrol a supporting vehicle while also controlling a manipulator arm.Using such devices with both hands could provide simultaneous 24 axiscontrol.

In accordance with a further aspect of the invention, a finger operatedsix degree of freedom input device may be appended to any number ofotherwise conventional control means such as flight control sticks,flight control yokes, steering wheels, rudder wheels, joysticks. controllevers, control pendants, and the like.

Such schemes may be useful for controlling a multi-axis manipulators ortools which may be attached to bases or vehicles which may require orbenefit from concurrent multi-axis control.

Yet another embodiment of the present invention may be in the form of amouth, jaw, or head operated controller for use by quadriplegics, anapplication for which the prior art designs may be too bulky.

In accordance with another aspect of the invention, the entire devicemay be hand held and portable and the active grip may be manipulatedwith respect to a base portion which may remain fixed relative to theuser's grasped hand or fingers, thus allowing the device to be held andused with only one hand. Alternatively, a portion of the base may besecured to the user's wrist or palm such as by strap or glove means.Signal transmission for such hand held configurations may even bepreferably by wireless means. The coordinate system for such a hand heldconfiguration may be relative to the fixed portion of the device withinthe user's hand or relative to external coordinates determined by somecombination of criteria such as radio signals, laser signals, gyrosignals, magnetic orientation and gravitational orientation. Suchportable embodiments may incorporate other devices such as orientationsensors, accelerometers, gyroscopes, etc.

In accordance with a further aspect of the invention, wrist or forearmmounting of the above described “hand held” configuration may allow forthe incorporation of a hinge for temporarily swinging the active gripout of the way of the operator's hand.

In accordance with yet another aspect of the invention, a six-axissensor assembly may be situated between two handles, such that therelative motion of the two handles may generate a corresponding signal.The handles may, for example, be the two halves of a two handed gameconsole similar to those used in conjunction with the Sony Playstation®or the Microsoft X-box®.

In accordance with another aspect of the invention, the device may be ofsufficiently small size to be incorporated into a computer keyboard,into a hand held computer, or into another control handle or device, andthe like.

A joystick for operation of construction equipment could be able to beoperated with large deliberate hand motions while wearing insulatedwinter gloves, for example. In such circumstances, a finger operatedfine-range-of-motion joystick may not be practical due to overwhelmingvibrations and machinery movements as well as lack of fine finger tiptactile feedback. Accordingly, several aspects and embodiments of thisinvention may address a need for a larger range of motion as follows:

In accordance with one aspect of the invention, the active grip may beprovided with an enhanced range of movement by means of one or moreflexible elements to which the sensor base may be attached.

In accordance with a further aspect of the invention, flexible elementsmay be configured to minimize any unintended coupling between axes. Thismay be accomplished for example by fixing the base of a limited range ofmotion multi-axis joystick (of either this invention, prior art orfuture art) to a first mounting block to which the upper ends of 3 ormore flexible and generally parallel rods are fixed. The lower end ofthe flexible rods may be fixed to a second mounting block. The first andsecond mounting blocks will tend to remain parallel despite deflectionsin a horizontal plane. In other words, horizontal translationalflexibility is thus provided without unintended and undesirable couplingto the horizontal rotational axes. The second mounting block may bemounted on a pair of offset but generally parallel leaf springs. Theother end of the generally parallel leaf springs may be fixed relativeto the operator. The leaf spring assembly provides torsional stiffnessin all three axes while permitting significant z-axis motion of thejoystick grip.

In accordance with a further aspect of the invention, a transducer meansand other moving parts may be protected from damage and contamination bya flexible bellows.

In accordance with a further aspect of the invention the bellows may bedesigned to exhibit significant torsional compliance about the bellowsaxis of symmetry, which is generally not the case with conventionalbellows. Such torsional compliance may be provided by convolutions ofalternating orthogonal orientation, for example.

In accordance with a further aspect of this invention, a second bellowsmay be provided, either connected or not connected to the movingmechanism, for the purpose of equalizing pressure within a bellowsprotected cavity. This aspect may be particularly important forfacilitating Z-axis movement without causing pressure differences orcontamination due to otherwise required ventilation.

In accordance with another aspect of the invention, a wrist rest may beprovided which is movable with and associated with the active grip butwhich may support gravity and acceleration loads of the user's armseparately from the active grip. In this manner, the user's arm may bedesirably supported to reduce fatigue, while allowing large rangejoystick movements, which may be desirable in high vibrationenvironments such as operation of construction equipment. Measurement ofthe instantaneous weight of the user's arm may be accomplished by meansof separate load cell(s) associated with the wrist rest, for example.

Various additional modifications and improvements which may increase theusefulness of this invention are described as follows:

In accordance with a further aspect of the invention, a multi-axistransducer in accordance with the present invention may be affixed to anotherwise conventional Stewart platform or equivalent such that saidmulti-axis transducer may generate an operator originatedforce/displacement signal while the underlying Stewart Platform orequivalent supplies force and position feedback to the operator. Such anarrangement may also be used to provide increased displacements comparedto those provided by the multi-axis transducer itself.

In accordance with another aspect of this invention, fiber optic guidesmay be used to emit and receive light within the transducer assembly,for example, which may eliminate electrical power components from thetransducer vicinity for uses such as controlling a bucket truck boom orrobotic arm used to service high voltage power lines, and the like. Afiber optic connected version of the present invention could also beuseful for construction of an extremely small multi-axis positiontransducer which could be applicable to miniature robotics, themanufacturing of small scale electrical and mechanical devices, as wellas to micro biology and medical applications and the like.

In accordance with another aspect of the invention, the transducerelement of this invention may be used as a six-axis accelerometer ormotion sensor by attaching a reference mass to the movable mirrorassembly.

In accordance with another aspect of the invention, the displacementtransducer element of this invention may be used as a general-purposemulti-axis displacement measuring means.

In accordance with a further aspect of the invention, a noise-cancelingelement may be provided to reduce noise from ambient vibrations. Forexample, accelerometers mounted to the base of the device may be used tocancel out spurious signals such as those caused by vehicle vibrations.

Various aspects of this invention may be utilized in order to reduce incost and make more compact embodiments of the prior art. For example,the use of mirror elements of this invention in conjunction with thelight transducer circuitry and shading means of Hilton et al. mayfacilitate the use of a single circuit board or monolithic phototransducer. In this example, the mirrors could be stationary and theshading means may be movable or the shading means could be movable andthe mirrors stationary. Alternatively, fiber optic or light guideelement(s) could be used instead of mirrors in order to reverse thedirection of the light paths or to distribute the light from a singlesource to light paths of suitable orientation and geometry.

A further embodiment may incorporate a plurality (six, for example) ofmagnetic flux sensors such as Hall Effect transducers or Giant MagneticEffect (GME) transducers onto a single printed circuit board which maybe movable in multiple degrees of freedom, six for example, relative toa magnetic flux structure which may be established by a single magnetfor example. Said embodiment may shield the magnetic flux sensors fromambient magnetic fields by means of a flux conducting magnetic grip orportion thereof, which may provide a flux path (for externally imposedmagnetic fields) around the magnetic flux sensors along any requireddirection. A ferromagnetic pole piece, for example, may be used todirect magnetic flux in a manner which establishes easily measuredmagnetic flux gradients at the magnetic flux sensors, thus renderingdetectable displacement of the flux paths relative to the detectors. Theflux may, for example, be directed along three paths with each magneticflux path intercepting two magnetic flux detectors. The magnetic fluxsensors may be located and oriented relative to the flux paths such thatthe motion sensitive axis, i.e., the direction in which the derivativeof the cross products of magnetic flux and the axis of maximum magneticflux detector sensitivity with respect to displacement are maximum.

Alternatively, magnetic flux gradient detectors, such as MEMS devicesincorporating microscopic magnets on force transducers may be used in asimilar manner wherein the second derivative of flux density would beoriented and optimized relative to sensor sensitive axis orientation.

According to yet another aspect of the invention, line frequency noisecould be electronically filtered from the output signal.

According to a further aspect of the invention, additional loopedcircuit paths with or without separate resistors could be provided inthe circuit board to provide magnetic damping of the spring suspendedassembly. Such damping may be helpful in a vibration prone environmentsuch as in construction equipment control applications.

A further embodiment may utilize an elastomeric or elastic structure tomeasure deflections of an active grip, for example. In a simpler form,such an embodiment may be comprised of a single conductive elastomericstructure and associated electrical terminals attached thereto. Theconductive elastomer may preferably be ionically conductive, whichproperty results in a smooth and useful strain-resistance curve incontrast to conductive particle filled elastomers which may exhibit lessuseful strain-resistance characteristics.

According to a further aspect of the invention, a single piece ofconductive elastomer may be configured in the shape of a StewartPlatform or its functional equivalent.

According to a further aspect of the invention, multiple segments ofconductive elastomer may be configured in the general shape of a StewartPlatform or its functional equivalent.

Alternatively, a deformable structure of conventional (likelynon-conductive) elastomer may be used to contain a dielectric fluid orconductive fluid such as an electrolyte solution. Said dielectric fluidor conductive fluid may cause the electrical relationship between aplurality of electrodes immersed therein to vary as the shape of thecavity or cavities in which said fluid is contained changes shape withdeformation of said deformable structure. In the case of either of theaforementioned elastomeric structures, the gauge factor may be muchhigher than for conventional strain gauges due to the generally higherelongation of elastomers compared to metal or semiconductor strain gaugematerials.

According to a further aspect of the invention a single cavity within anelastomeric structure containing a conductive or dielectric fluid may beconfigured in the shape of a Stewart Platform or its functionalequivalent. The walls of such a cavity are preferably convoluted alongseveral orthogonal directions to allow deformation in six degrees offreedom and relatively uniform stiffness among the various axes.

According to a further aspect of the invention, multiple cavitiescontaining conductive or dielectric fluid may be configured in the shapeof a Stewart Platform or its functional equivalent.

According to a further aspect of the invention, a deformable elastomericstructure may be provided that may be configured for attachment of aplurality of single axis displacement transducers. Such a structure maybe very inexpensive and may facilitate simple zero-backlash mounting ofinexpensive displacement transducers.

According to a further aspect of the invention, a plurality of cavitiesmay be provided in the configuration of a Stewart Platform or itsfunctional equivalent, wherein said cavities may be connected topressure transducer means.

According to a further aspect of the invention, a plurality ofstiffeners are provided within an elastomeric structure, wherein saidstiffeners transmit strains to transducer means such as MEMS devices orstrain gages. Said stiffeners may be configured in the generalconfiguration of a Stewart Platform or it functional equivalent.

According to a further aspect of the invention, various ergonomicarrangements of the present invention may be utilized in conjunctionwith video or other non-contact position sensing means instead of by wayof the sensor means disclosed herein. For example, the 12 axis joystickof FIGS. 35 a through 35 g could be used to provide a consistentinterface for the operator(s), while measurement of the active grippositions and/or hand positions may be accomplished by one or more videocameras, for example. Such an arrangement may be superior for someapplications to schemes for interpreting completely free form handgestures by way of video measurement.

According to a further aspect of the invention, multiple actuatablesensor stages such as those comprised of multiple inflatable cavities oractuators may be mounted in series to create a snake-like robotic devicewith many degrees of freedom.

Many of the above multi-axis joysticks produce, for example, six analogsignals which may need to be nonlinearly transformed to position androtation deflections with respect to the x, y, and z axes. Manyalternative methods and algorithms may be used to derive from thetransducers of a multi-axis joystick a signal of desired usefulness. Thefollowing is but one example of a general method of deriving a usefulsignal.

The transformation may be multi-stage, and may consist primarily of alinear diagonalization and a nonlinear scaling and correction. A cubicpolynomial transformation may be used to model the nonlinear mappingfrom signals to outputs. A full cubic polynomial with six inputvariables has 6*4^6=24576 coefficients, and may be too computationallycostly to be useful. A better transformation may consist of anapproximate linear transformation to achieve nearly diagonal outputsfollowed by a polynomial transformation with all terms up to total 3rdorder (e.g., (1, x, y, x^2, x*y, y^2, x^3, x^2*y, x*y^2, y^3) for 2variables). This requires 6*6=36 coefficients for the lineardiagonalization transform and 504 coefficients for the nonlinear cubicpart, which may be computationally feasible. An initial pre-transformusing 6 coefficients might be done on each production unit to accountfor manufacturing variations in the individual sensors. A finalpost-transformation which rescales the translation, rescales therotation, and centers the output (tares) requires 1+1+6=8 coefficients,might be specified per user preference.

For any particular prototype design, the 36 pre-transform coefficientsand 504 nonlinear transform coefficients might be calculated as follows:Each axis may be sampled at positive, zero, and negative locations in a6-cube grid, yielding 3^6=729 sample points (e.g., center, forward,forward and up, forward and left-twist and nose-down-twist, etc.) atcenter and extreme positions. The 36 linear transform coefficients maybe fit with a least-squares solution to best diagonalize the output.Using these coefficients, the sample data may be linearly transformed toproduce an approximately linear data set. Then the 504 nonlineartransformation coefficients may be fit, again using, for example, alinear least squares solution.

Once a design prototype has been calibrated, each production unit mightuse the same 36 linear transform coefficients and the same 504 nonlineartransform coefficients, but a one-time calibration of the 6 sensorscaling coefficients might be done at first use, or possibly beforesale. Each user might specify, for example, a single translationsensitivity coefficient and a single rotation sensitivity coefficient tosuit preference. At the time of initial use and possibly throughout eachuse of the device, the output might be centered (tared) using 6coefficients to account for minor variations in temperature,orientation, or the user's hand weight, etc.

IV. BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 a through 1 e all depict various views generated from aSolidWorks® solid model of one of the preferred embodiments of a sixaxis joystick constructed according to this invention.

FIG. 1 a is a plan view looking down the Z-axis of said six-axisjoystick with example light paths depicted.

FIG. 1 b is a sectional cutaway elevation view showing the majorcomponents of said joystick.

FIG. 1 c is a cutaway perspective view showing the major components ofsaid joystick.

FIG. 1 d is an elevation view of said joystick.

FIG. 1 e is an exploded view depicting the salient components of saidjoystick.

FIG. 2 is a perspective view of the active grip of said joystickdepicting the internal reflective facets.

FIG. 3 is a schematic of a cylindrical projection of a six-axis joystickin accordance with the present invention in conjunction with one type ofassociated electrical schematic.

FIG. 4 is a schematic of a cylindrical projection of a six-axis joystickin accordance with the present invention with illustrating the functionof curved mirror facets.

FIG. 5 is a schematic of a cylindrical projection of an embodiment ofthe present invention shown in conjunction with a correspondingelectrical schematic illustrating the implementation of touch sensingmeans and truncated mirror facets.

FIG. 6 is a perspective view of integrated photo emitter/photo detectorpackage in accordance with one embodiment of the present invention.

FIG. 7 is a schematic of a cylindrical projection of another embodimentof a six-axis joystick in conjunction with a corresponding electricalschematic.

FIGS. 8 a through 8 e all depict various views generated from aSolidWorks® solid model of another of the preferred embodiments of a sixaxis joystick constructed according to this invention.

FIG. 8 a is a plan view looking down the Z-axis of said six-axisjoystick with example light paths depicted.

FIG. 8 b is a sectional elevation view showing the major components ofsaid joystick.

FIG. 8 c is a cutaway perspective view of said joystick.

FIG. 8 d is an elevation view of said joystick.

FIG. 8 e is an exploded view depicting some salient components of saidjoystick.

FIG. 9 is a perspective view of the active grip of said joystickdepicting the internal reflective facets.

FIG. 10 a is a cross section view of an embodiment of the presentinvention featuring a traditional “joystick” style active grip, anenhanced range of motion, and protective and pressure compensatingbellows.

FIG. 10 b is an additional cross section view of the embodiment of FIG.10 a.

FIGS. 11 a, 11 b, 11 c and 11 d are plan, cross-sectional, perspective,and exploded views respectively of an example magnetic flux sensorembodiment of the present invention.

FIG. 12 is a plan view of a magnetic element of an embodiment of thepresent invention.

FIG. 13 a is a plan view of an assembled magnetic element of anembodiment of the present invention.

FIG. 13 b is a cross-sectional elevation view of a magnetic embodimentof the present invention.

FIG. 14 is a printed circuit board detail of an embodiment of thepresent invention.

FIG. 15 a is a sectional view of an elastomeric embodiment of thepresent invention.

FIG. 15 b is an exploded view of the embodiment of FIG. 15 a.

FIG. 15 c is an assembled, transparent view of the embodiment of FIG. 15a

FIG. 15 d is another exploded view of the embodiment of FIG. 15 a.

FIG. 15 e is sectional view similar to FIG. 15 a.

FIG. 16 is a sectional elevation view of another elastomeric embodimentof the present invention.

FIG. 17 is a representative equivalent circuit of an elastomericembodiment of the present invention.

FIG. 18 a is an elevation view of the sensor portion of yet anotherelastomeric embodiment of the present invention.

FIG. 18 b is another elevation view of the sensor element depicted inFIG. 18 a.

FIG. 18 c is a plan view of the sensor element depicted in FIG. 18 a,

FIG. 18 d is a perspective view of the sensor element depicted in FIG.18 a.

FIG. 18 e is a representative equivalent circuit of the sensor elementdepicted in FIG. 18 a.

FIGS. 19 a, 19 b, 19 c, and 19 d are respectively, a perspective view,an elevation view, another elevation view, and a plan view of a sensorassembly in accordance with yet another elastomeric embodiment of thepresent invention.

FIG. 19 e is a representative equivalent circuit of the sensor assemblyof the elastomeric embodiment of the present invention as it is depictedin FIGS. 19 a, 19 b, 19 c, and 19 d.

FIGS. 20 a and 20 b are plan view and sectional elevation view of one ofseveral electrolyte filled elastomeric embodiments of the presentinvention.

FIGS. 21 a, 21 d, 21 e, and 21 f are, respectively, a plan view, anelevation view, another elevation view, and a perspective view of anassembly of another electrolyte filled elastomeric embodiment of thepresent invention.

FIG. 21 b is a view of a single transducer subassembly of the transducerassembly depicted in FIGS. 21 a, 21 d, 21 e, and 21 f.

FIG. 21 c is section A-A taken through FIG. 21 b.

FIG. 22 is a sectional schematic cut along a hexagonal of path yetanother electrolyte filled elastomeric embodiment of the presentinvention shown during representative stages of manufacture andassembly.

FIG. 23 is a partial sectional schematic cut along a hexagonal path ofyet another electrolyte filled elastomeric embodiment of the presentinvention.

FIG. 24 is a partial sectional schematic cut along a hexagonal path ofyet another electrolyte filled elastomeric embodiment of the presentinvention.

FIG. 25 a is an elevation view of an elastomeric embodiment of thepresent invention utilizing a combination of stiffening elements andforce sensors.

FIG. 25 b is an elevation view of another elastomeric embodiment of thepresent invention utilizing a combination of stiffening elements andforce sensors.

FIG. 25 c is a plan view depicting one of many possible stiffenerarrangements.

FIG. 26 is a partial sectional view showing one element of themulti-axis sensor portion of an elastomeric embodiment of the presentinvention utilizing a combination of stiffening means and pressuresensing means.

FIG. 27 is a sectional view of an embodiment of the present inventiondepicting the use of discrete single axis displacement sensors inconjunction with a deformable elastomeric structure.

FIG. 28 is a representative partial sectional view of another embodimentof the present invention depicting the use of discrete single axisdisplacement sensors in conjunction with a deformable elastomericstructure.

FIG. 29 is a representative partial sectional view of yet anotherembodiment of the present invention depicting the use of discrete singleaxis displacement sensors in conjunction with a deformable elastomericstructure.

FIG. 30 is a representative partial sectional view of the sensor portionof yet another embodiment of the present invention depicting the use ofextendable coiled variable inductors embedded within a deformableelastomeric structure.

FIG. 31 is a representative partial sectional view of the sensor portionof yet another embodiment of the present invention depicting the use ofextendable coiled variable inductors embedded within a deformableelastomeric structure in conjunction with a plurality of cavities whichmay be deformed by internal pressure for force or position feedbackpurposes.

FIGS. 32 a, 32 b, 32 c, and 32 d are, respectively, sectional elevation,partial plan, partial sectional elevation, and perspective views of anembodiment of the present invention featuring an electrolyte filleddeformable sensor, a gel filled wrist rest and an integral data entrykeypad.

FIG. 33 is a schematic representation of an embodiment of the presentinvention comprising a two handed game controller with a multi-axissensor means connecting the right and left gripped portions of said gamecontroller.

FIG. 34 is a schematic illustration of a hand held embodiment of thepresent invention.

FIGS. 35 a, 35 b, 35 c, 35 d, 35 e, 35 f, 35 g, and 35 h are photographsof a model of an embodiment of the present invention comprising a fingertip operated active grip of approximately 1.5 inch diameter, with sixdegrees of freedom for example, mounted to a hand held active grip, withan additional six degrees of freedom, for example.

FIGS. 36 a and 36 b are photographs of a model of an embodiment of thepresent invention similar to that shown in FIGS. 35 a through 35 h,except with a finger-tip operated grip of approximately 1 inch diameter.

FIGS. 37 a and 37 b are photographs of an embodiment of the presentinvention wherein a fingertip active grip is mounted to a fixed handstabilizing grip wherein said fingertip operated active grip is anapproximately 1.5 inch diameter sphere.

FIGS. 38 a, 38 b, 38 c, and 38 d are photographs of a model of anembodiment of the present invention similar to that shown in FIGS. 37 aand 37 b, except that the fingertip operated grip is a sphere ofapproximately 1 inch diameter.

FIG. 39 is an electrical schematic of a bridge circuit corresponding toan elastomeric embodiment of the present invention.

FIG. 40 a is a perspective view of an elastomeric sensing element inaccordance with one of the embodiments of this invention.

FIG. 40 b is a cross sectional view of the sensing element of FIG. 40 a.

FIG. 41 is an elevation view of an embodiment of the present inventionthat incorporates a plurality of electrically conductive elastomerictensile members.

FIG. 42 is a representative electrical schematic of one embodiment ofthe present invention.

FIG. 43 is a representative electrical schematic of another embodimentof the present invention.

FIG. 44 is a schematic of an electrolyte filled cavity of StewartPlatform geometry within a deformable elastomeric sensing element inaccordance with one embodiment of the present invention.

FIG. 45 is an electrical schematic corresponding to the embodiment ofFIG. 45.

FIG. 46 is a cross section of one embodiment of the present invention.

FIG. 47 is an illustration of one exemplary relationship between a threephase excitation signal and an output signal from one embodiment of thepresent invention.

FIG. 48 is a view of a printed circuit board arrangement which might beused in conjunction with the embodiment of FIG. 46.

FIG. 49 a is a plan view of one embodiment of the present inventionwherein a base portion of a six axis joystick is stabilized by a gel padwrist rest.

FIG. 49 b is a sectional elevation view of the embodiment shown in FIG.49 a

FIG. 49 c is an exploded view of the embodiment shown in FIG. 49 a.

FIG. 49 d is a perspective view of a portion of FIG. 49 a.

FIG. 50 a is a cutaway view of one embodiment of the present inventionfeaturing a monolithic optical position transducer.

FIG. 50 b is an exploded view of the embodiment of FIG. 50 a.

FIG. 50 c is a perspective view of the monolithic position transducerfrom FIG. 50 b.

FIG. 51 a is a perspective view of a finger operable joystick appendedto a three axis mouse.

FIG. 51 b is a bottom view of the embodiment of FIG. 51 a.

FIG. 51 c is an end view of the embodiment of FIG. 51 a.

FIG. 51 d is a side view of the embodiment of FIG. 51 a.

FIG. 51 e is a top view of the embodiment of FIG. 51 a.

FIG. 51 f and FIG. 51 g are perspective views of the embodiment of FIG.51 a.

FIG. 52 is a perspective view of an embodiment of the present inventionincluding a loader equipped with sensors to facilitate coordinatetransformation for control of a stewart platform adaptor using ajoystick.

FIG. 53 is a schematic diagram of an example control scheme for theembodiment of FIG. 52.

FIG. 54 a is a cross section of a monolithic transducer.

FIG. 54 b is a partial edge view of the embodiment of FIG. 54 a

FIG. 55 is a sectional elevation of a joystick in accordance with oneaspect of this invention.

FIG. 56 a is a cross section of a joystick in accordance with oneembodiment of this invention including two coaxial springs placedsymmetrically with respect to the transducing element.

FIG. 56 b is an example reflective pattern.

FIG. 56 c is an example reflective pattern.

FIG. 57 is a schematic depicting an example null state angular and axialalignment of transducer and reflective pattern.

FIG. 58 is an example stress analyses of a spring used in one aspect ofthis invention.

FIG. 59 is another example of a stress analyses of a spring used in oneaspect of this invention.

FIG. 60 is an example of a spring with a single elastic element inaccordance with one aspect of this invention.

FIGS. 61 a and 61 b are simulated images incident on the transducer ofone embodiment of this invention.

V. MODES FOR CARRYING OUT THE INVENTION

A multi-axis input transducer apparatus may comprise an at least quinaryinput element capable of input with respect to at least five frames ofreference, a reflective element responsive to radiation from a sourcecapable of emitting radiation eventually incident upon said reflectiveelement and at least one reflected radiation detector responsive toradiation from said reflective element. The term reflection is usedbroadly to include refraction of said radiation. Referring to FIGS. 1 a(plan view), 1 b (sectional elevation view), 1 c (cutaway perspectiveview), 1 d (elevation view), and 1 e (exploded view), a preferredembodiment of a six-axis joystick in accordance with the presentinvention is shown. Active grip 1 may incorporate reflective facets 2 a,2 b, 2 c, 2 d, 2 e, and 2 f. Said reflective facets or reflector may bealigned such that each reflects the light from light source or radiationsource 4 (which may be a light emitting diode) to a photo detectionelement or other reflected radiation sensor at one particular location.Said photo detection element may be photodiodes, phototransistors, photoresistors, or other suitable light detection means, or fiber optic portsleading to such detection means at another location such as on an ASIC(application specific integrated circuit chip). Active grip 1 may beheld in position by a restoration element such as coil spring 10, whichmay be angularly located in the active grip by recess 11 and in the base3 by recess 12. A means such as a light baffle 6 may be used to preventdirect illumination of detector(s) 5 a, 5 b, 5 c, 5 d, 5 e and 5 f bylight source 4. Said light baffle 6 may also be configured to assist inlocating and orienting said light source 4 and perhaps photo detectors 5a, 5 b, 5 c, 5 d, 5 e and 5 f during soldering, for example. Said baffle6 may be used to retain printed circuit board 13 by means of screws 7.Some retaining means such as screws 8 or pins may be provided to limitthe travel of the active grip perhaps so that maximum travel of activegrip 1 remains within the measurement range of the optical elements suchas photo detectors 5 a, 5 b, 5 c, 5 d, 5 e, and 5 f in conjunction withreflector element(s) within active grip 1 and light source 4, andperhaps so that said maximum travel remains within the elastic range ofrestoring means such as spring 10, and within the various mechanicalclearances between the movable and stationary components. The contactcharacteristics between said retaining means 8 and associatedreceptacles 9 may be optimized by friction reduction element and/orenergy absorption element such as coatings or bushings.

Referring to FIGS. 1 a and 1 d, light paths 14 may no not lie in radialplanes but instead may follow paths, which may be controlled, by thelocations and orientations of the various mirror facets. By means ofthis arrangement, the lengths and alignments of the light path to the 6photo detectors may uniquely define the position of the active grip inthe x, y, z, Θx, Θy, and Θz degrees of freedom. In general thebrightness may also vary as the inverse square of the effective lightpath distance. The sensitivity of brightness with respect to mirrorfacet position may be maximum for movements of any mirror facet along anaxis normal to the surface of said mirror facet. Said axes normal tosaid mirror facets may comprise a virtual octahedral hexapod or “StewartPlatform”. Movements along either axis normal to the said first axis mayhave no effect on light path length or brightness. Extreme movementscould of course shift said mirror facet completely off of said lightpath, but such extreme movements are not required and may be, in fact,prevented by mechanical stops. Angular movements about an axis normal tosaid mirror facet may have no effect on said light path. Angularmovements about any axis lying in the plane of said mirror segment maysimply cause a lateral shift in the point of reflection of said lightpath with only negligible second order effects on light path distance.

Said effective light path distance corresponding to the null position ofthe active grip can be optimized as a design variable by means of lenselements associated with the light source, the photo detectors and/or bycurvature of the reflective facets. For example, a virtual image of thelight source may be created at a position closer than the distancecorresponding to the physical light path in order to obtain a greaterchange in brightness for a given change in mirror facet movement.Spatial distribution of illumination by the light source and spatialdistribution of light sensitivity of the light detectors may also beadjusted by the use of lens elements. The changes in alignment of theemitters, mirrors, and detectors may also be used advantageously togenerate photo detector signals that represent the mirror facetpositions. If any particular light path from an emitter straddles anedge of a mirror or the edge of a detector assembly, any relativemovement of said light path and said edge may create a significantchange in measured light intensity.

The aforementioned discussion of function and geometry may apply equallyto an embodiment wherein a single photo detector, which could in saidembodiment be designated as item 4 in the various FIG. 1 views,sequentially measures light intensity from a plurality of light emitters5 a, 5 b, 5 c, 5 d, 5 e, and 5 f in the FIG. 1 views. In said embodimentsaid light emitters may be cycled in a circular pattern for example, toenable individual light intensities and thereby light path distances tobe measured. The use of a single photo detector may facilitate the useof a single channel analog to digital converter which could be timemultiplexed in synchronism with illumination of the plurality of lightemitters.

Referring to FIG. 3, a cylindrical projection schematic is shown inconjunction with a schematic of one of many alternative possibleelectrical arrangements. The optical elements depicted in FIG. 3 may bethe same as those depicted in FIGS. 1 a, 1 b, 1 c, 1 d, and 1 e. Photodetectors 5 a, 5 b, 5 c, 5 d, and 5 e may be physically distributed as ahexagonal array around photo emitter 4, which is shown schematically onthe right hand side of FIG. 3, but which may be located for schematicpurposes directly behind each of said photo detectors. Mirror facet 2 amay reflect light from photo emitter 4 onto photo detector 5 b. Mirrorfacet 2 b may reflect light from photo emitter 4 onto photo detector 5a. This pattern may be repeated for a total of six light paths, thelengths of which define the exact position and orientation of the activegrip and its mirror facets in six degrees of freedom. Coil spring 10(which physically supports active grip 1 shown schematically on the lefthand side of FIG. 3) is shown electrically connected to grip 1 and touchdetection circuit 15. Grip 1 may incorporate a separate capacitive touchswitch element, if required, or may utilize the mirror coating such asthat on mirror facet 2 a to accomplish the capacitive touch switchfunction. “Active grip” is herein used to mean that portion of amulti-axial input device gripped and moved by the user relative to theuser's frame of reference. The outputs of photo detectors 5 a, 5 b, 5 c,5 d, 5 e, and 5 f are shown connected to amplifiers 18 a, 18 b, 18 c, 18d, 18 e and 18 f and resistors 19 a, 19 b, 19 c, 19 d, 19 e, and 19 f.The output of said amplifiers is shown connected to a programmableinterface controller (PIC®) 16 from which device the signal(s) may go toa signal-receiving device 17 such as a computer or robot. The axes ofsix degrees of freedom are labeled at the top of FIG. 3.

Referring now to FIG. 4, while flat mirror facets are depicted in theFIGS. 1 a, 1 b, 1 c, 1 d, 1 e, 2, and 3, the curved facets schematicallyillustrated in FIG. 4 may be used advantageously to obtain greatersensitivity and resolution for particular applications. Light 14 fromemitter 4, which is hidden from direct view in FIG. 4, may be focused bymirror facet 2 a to form an image of said emitter 4 at a distance L fromphoto detector 5 b. For clarity, the light between emitter 4 anddetector 5 a is not shown in FIG. 4.

Referring now to FIG. 5, mirror assembly and active grip 1 mayincorporate truncated mirror facets 2 a, 2 b, 2 c, 2 d, 2 e, and 2 f.Light from emitter 4 may follow paths 14 which may impinge of the edgesof mirror facets 2 a, 2 b, 2 c, 2 d, 2 e, and 2 f. That light whichstrikes said mirror facets may reach photo detectors 5 a, 5 b, 5 c, 5 d,5 e and 5 f. That portion of light which strikes light absorbent surface41 may not reach said detectors. This arrangement is thus sensitive tothe relative movement of the edges of mirror facets 2 a, 2 b, 2 c, 2 d,2 e, and 2 f.

Referring now to FIG. 6, a monolithic photo transducer package is showncomprised of casing 44, photo detectors 42 a, 42 b, 42 c, 42 d, 42 e,and 42 f, photo emitter 43, and electrical connection 45. Such amonolithic transducer may be more robust than printed circuit boardmounted transducers and may thus not be subject to optical misalignmentdue to handling during manufacture or due to high g forces due to beingdropped on the floor for example. The monolithic package may also beadvantageously used to grind flush and thereby remove the collimatinglenses that are standard as-manufactured features of many discrete phototransducer components. Although not depicted in FIG. 6, such amonolithic package may also be configured to retain a spring used tosupport the active grip.

Referring now to FIG. 7, detectors 46 a, 46 b, 46 c, 46 d, 46 e, and 46f may be located such that light paths 14 straddle their edges. Anymovement, due to movement of active grip 1, of light paths 14 normal tosaid edges may thus cause a change in brightness.

Referring to FIGS. 8 a (plan view), 8 b (sectional elevation view), 8 c(cutaway perspective view), 8 d (elevation view), and 8 e (explodedview), a preferred embodiment of a six-axis joystick in accordance withthe present invention is shown. Active grip portion 1 a, also shown byitself in FIG. 9, may incorporate reflective facets 2 a, 2 b, 2 c, 2 d,2 e, and 2 f. Active grip portion 1 c may retain active grip portion 1 bwhich has preferably a low durometer (<40 Shore A hardness) elastomer.Such a soft grip portion 1 a may provide a non-slip surface which may bereliably engaged by the operator's fingertips with minimal grippingforce. The compliance of the grip due to its low hardness in combinationwith significant thickness may reduce contact stresses on the operator'sfingers and thus may help prevent reduction in blood circulation. Saidgrip portion 1 b may be a standard O-ring shape. Grip portion 1 c mayfeature holes in bottom portion. The outer holes may provide apredetermined amount of clearance to stand off spacers 21. The relativediameters of holes 22 (taking into account grommets if used) and spacers21 may define the range of motion in a horizontal plane of the activegrip. Vertical clearances between grip portion 1 c and base 3 andbetween grip portion 1 c and circuit board 13 may provide apredetermined amount of vertical travel. The active grip assemblycomprised of portions 1 a, 1 b, and 1 c may be thus confined to apredetermined allowable extent of travel in six degrees of freedom.Active grip portion 1 a may be fixed to spring 10 by spring retaininggrooves 47 in active grip portion 1 a. Spring 10 may in turn be fixed tomonolithic transducer package 21 by groove 48. Said monolithictransducer package 21 may incorporate a circuit board 13 which mayextend outward radially to engage spacers 21 and screws 23.Alternatively, an additional separate piece may be used for mountingtransducer package 21 and engaging some mounting means such as spacers21 and screws 23.

Referring now to FIGS. 10 a and 10 b, an embodiment of the presentinvention featuring a traditional “joystick” style active grip, anenhanced range of motion, and protective and pressure compensatingbellows is shown in cross section. Transducer 25 may be similar to thatdescribed in FIG. 8 a, 8 b, 8 c, 8 d, and 8 e. Said transducer maynecessarily have a limited range of motion especially if it is to becontained within active grip 24. The arrangement shown is intended toprovide additional range of translational motion along three axes asfollows: Leaf springs 29 and 30 are fixedly mounted to mounting block28. Connection block 35, which may be nominally the same height asmounting block 28, can be deflected upward and downward along the Z-axiswithout motion about the Θx axis. Mounting block 36 may be attached to aplurality of beams 31, 32, 33, and 34 that may be in turn attached toconnection block 35. Moments of inertia about the Z-axis for beams 31,32, 33, and 34 are selected to provide a predetermined degree ofstiffness in torsion about the Z-axis. The spacing of beams 31, 32, 33,and 34 may be nominally the same at both connection block 35 and atmounting block 36. Horizontal deflections of mounting block 36 may nottherefore cause twisting of the active grip about the Θx or Θy axes. Thenominal equal spacings of the flexible elements at the various mountingpoints may be adjusted to achieve controlled amounts of coupling, ifdesired, of the various rotational and translational axes. Bellows 26may be similar to that used on conventional joysticks except that it maybe provided extra pleats to provide compliance about the Θz axis.Bellows 27 may compensate for air volume changes in housing 37 due toZ-axis movements of bellows 26. Bellows 27 may be preferably attached tomounting block 35 so that the movement of bellows 27 is directly handpowered and said bellows 27 therefore does not lag behind until asufficient air pressure differential might cause a sudden movement ofsaid bellows 27, which might in turn cause an unintended sudden movementof bellows 26 and therefore of transducer assembly 25, which could thuscause spurious signals. The small size of transducer assembly 25 mayfacilitate the use of a grip 24 that is small enough to allow reliablegripping even while the operator's thumb and forefinger are used toactuate typical game-style joystick buttons or triggers.

Referring to FIGS. 11 a, 11 b, 11 c and 11 d Permanent magnet 53 may beheld between (magnetic) spring grip 56 and (magnetic) pole piece 52 by(non-magnetic) stud 55 and nut 54. The lower end of (non-magnetic)spring 10 may be fixed to (non-magnetic) spring platform 51, which maybe shaped to engage said spring 10. Three (non-magnetic) spacers 21position (non-magnetic) spring platform 51 above magnetic pole piece 52and printed circuit board 13. Six magnetic flux sensors such as HallEffect sensors 50 a, 50 b, 50 c, 50 d, 50 e, and 50 f may be fixed toprinted circuit 13 and located such that displacement of the springsuspended assembly comprised of magnetic grip 1, spring grip 56, stud55, nut 54, and pole piece 52 along any translational axis or about anyrotational axis may produce a unique output signal from the combined setof magnetic flux sensors 50 a, 50 b, 50 c, 50 d, 50 e, and 50 f. Polepiece 52 may feature three poles: 52 a (located between magnetic fluxsensors 50 a and 50 b), 52 b (located between magnetic flux sensors 50 eand 50 f) and 52 c (located between magnetic flux sensors 50 c and 50d). Said poles, at the null position, are angularly, with respect to theZ-axis, located exactly between their respective magnetic flux sensors.In elevation view, each of said poles may be located above the planedefined by the position of the magnetically responsive elements withinsaid magnetic flux sensors. In this manner the vector dot products ofthe local magnetic flux and the maximum sensitivity axis of each of saidmagnetic flux sensors may create a pattern of signals uniquelyrepresenting the position of said spring suspended assembly. The sixvectors of maximum sensitivity (maximum change in signal of individualmagnetic flux sensors versus change in position of the respective pole)may define a shape in space similar to a hexapod or Stewart Platform.Spacers 21 and pole piece 52 may be shaped to limit the travel of saidspring mounted assembly in the horizontal plane or about the Z-axis.Downward movement (along the Z-axis) may be limited as the end of stud55 engages printed circuit board 13. Upward movement of said springmounted assembly may be limited as pole piece 52 engages spring platform51. Each of the contacting surfaces of pole piece 52, spacers 21,circuit board 13 and spring platform 51 could, of course, beappropriately covered with non-abrading impact absorbing material. Thismight be accomplished, for example, by rubber coating of pole piece 52and using a smooth acorn nut as nut 54 in conjunction with a nylon wearplate attached to the top of circuit board 13. A comfortable gripmaterial such as a soft rubber sleeve could be applied to outside ofgrip 1. Each said magnetic flux sensor may be preferably an integratedcircuit such as a type 3503 ratiometric, linear Hall-Effect sensor asmanufactured by Allegro Microsystems, Inc. which type includes anamplifier to facilitate subsequent signal handling. Signal handling maybe accomplished by any of numerous known methods such as by use ofanalog to digital conversion boards or programmable interface chips(PIC®) such as those manufactured by Microchip Corporation. Optionally,a de-Gaussing coil may be added to the assembly to reduce anyundesirable prior magnetization.

Referring to FIG. 12, a plan view of the flux path is shown without amagnetic grip. Referring to FIG. 13 a, a plan view is shown indicatingthe magnetic flux path with a magnetic grip. Referring to FIG. 13 b, themagnetic flux path 57 is shown in elevation view. The use of a returnmagnetic flux path through the grip may allow the flux to carry furtherfrom the pole pieces, resulting in better mechanical clearances, greaterrange of movement and better ergonomics.

Referring to FIG. 14, a circuit board 13 is shown with magnetic fluxsensors 50 a, 50 b, 50 c, 50 d, 50 e and 50 f. Damping circuits 58 and59 may be provided to serve a function similar to Amortisseur windingsin rotating electric machines. Discrete resistors may optionally beprovided in the damping circuits such as 58 and 59.

Referring to FIGS. 15 a through 15 e, grip 1 may be connected to theupper end of elastomeric sensing element 60.

It should be noted that the terms “upper” and “lower” are used simply tofacilitate description of the various drawings and are specificallyintended to not be limiting with respect to any disclosure or anyclaims. The various multi-axial input devices herein described are eachcapable of operating in any orientation with respect to gravity.

The lower end of elastomeric sensing element 60, which may be aconductive Elastomeric element, and which may be ionically conductive,may be fixed to pedestal 63, which may be fixed to base portion 64. Theupper end of sensing element 60 may be fitted with electrical terminals61 a, 61 b, and 61 c. The lower end of elastomeric sensing element 60may be fitted with electrical terminals 62 a, 62 b, and 62 c. Saidelectrical terminals may also be used for mechanical attachment of grip#1 and pedestal 63 to the elastomeric sensing element 63. Lower printedcircuit board 67 and upper printed circuit board 66 may be used tofacilitate electrical connection to elastomeric sensing element 60.Upper circuit board 66 may be fastened to elastomeric sensing element 60by means of fasteners 68 and may also be fastened to grip 1 by means offastener 69. Circuit board 67 may be clamped between pedestal 63 andelastomeric sensing element 60 by means of fasteners 65. Fasteners 65may also serve to attach pedestal 63 to base portion 64. Referring toFIG. 16, upper circuit board 66 may be configured to facilitate use ofmultiple fasteners 69 for attachment to grip 1. Referring again to FIGS.15 a through 15 d, upper electrical terminals 61 a, 61 b, and 61 c arepreferably equally spaced 120 degrees apart. Electrical terminals 62 a,62 b, and 62 c are also preferably equally spaced 120 degrees apart andare also preferably offset angularly from upper electrical terminals by60 degrees. In this manner, the electrically conductive elastomericsensing element 60, in combination with said electrical terminals, mayfunction as a variable resistance circuit as represented in FIG. 17.Note that FIG. 17 is a planar representation of a three dimensionalelectrical circuit, which may be thought of as a cross section of theelastomeric sensing element 60 of FIG. 15 a through 15 e cut alongeither a circular or hexagonal pattern intercepting electrical terminals61 a, 61 b, 61 c, 62 a, 62 b, and 62 c. Referring again to FIG. 17,variable resistor 70 a, for example, may represent the Variableresistance between electrical terminals 61 a and 62 a, which resistancemay vary as elastomeric sensing element 60 is deformed. Said threedimensional electrical circuit may be in the general shape of theactuator geometry of a Stewart Platform. Importantly, six degrees offreedom of the deflections of elastomeric sensing element 60 may beuniquely represented by the resistive electrical characteristics betweenelectrical terminals 61 a, 61 b, 61 c, 62 a, 62 b, and 62 c. Elastomericsensing element 60 may be made from a wide variety of materials ofseveral classes. In one embodiment of this invention, the elastomericmaterial may be a solid solution of a metal salt dissolved in a polymer,such as that described in U.S. Pat. Nos. 5,898,057, 6,063,499,6,111,051, or 6,184,331 to Chiang et al. or as commercially availablefrom Mearthane Products Corp. In the case of said solid solution of ametal salt dissolved in a polymer, the electrical excitation signal ispreferably of alternating polarity. Such an elastomer may be referred tohereafter as ionically conducting. For example, a three phasealternating current supply may be used as depicted in FIG. 45.Alternatively, the elastomeric sensing element 60 may be an“intrinsically conductive polymer” (ICP) such as Polyaniline(PAni)developed by Zipperling Kessler & Co. or blends of such polymers.Alternatively, polymers with conductive fillers may be used but may notbe preferred due to inconsistent and often non-linear strain-resistivityrelationships.

Referring to FIGS. 18 a, 18 b, 18 c, and 18 d, various views are shownof another Embodiment of an elastomeric sensing element 60 of thisinvention. Upper electrical terminals are designated 61 a, 61 b, and 61c. Lower electrical terminals are designated 62 a, 62 b, and 62 c. Thisembodiment may be superior to the embodiment of FIGS. 15 a through 15 edue to a reduced or eliminated electrical current through equivalentresistances 71 a, 71 b, 71 c, 71 d, 71 e, and 71 f as depicted in FIG.17. Additionally, the mechanical stiffness along the various axes may bereadily tailored by controlling the shapes and angles of the elastomeric“legs” 70 a, 70 b, 70 c, 70 d, 70 e, and 70 f.

Referring to FIG. 18 e, a representative equivalent circuit is shownwherein variable resistances 70 a through 70 f represent the resistancesof the “legs” of the same designation in FIGS. 18 a through 18 d.

Referring to FIGS. 19 a, 19 b, 19 c, and 19 d, various views are shownof yet another embodiment of the current invention wherein a pluralityof discrete elastomeric sensing elements 75 a, 75 b, 75 c, 75 d, 75 e,and 75 f may replace the single elastomeric sensing element 60 of thepreceding figures. Electrical terminals 72 a through 72 f and 73 athrough 73 f may fix said elastomeric sensing elements to upper circuitboard 66 and lower circuit board 67. The upper circuit board 66 andlower circuit board 67 may be fixed to a grip and pedestal or baseportion as depicted in other views. The size and shape of the discretesensing elements may be selected to optimize the stiffnesscharacteristics, strength, and ergonomic feel along each axis.

Referring to FIG. 19 e, a representative equivalent circuit is showncorresponding to the plurality of elastomeric sensing elements of FIGS.19 a through 19 d.

Referring to FIG. 20 a and FIG. 20 b, a plan view and cross sectionview, respectively, are shown of another embodiment of the presentinvention wherein a cavity 76 containing an electrically conductingliquid or gel, hereinafter referred to simply as “electrolyte”, may beprovided within a deformable elastomeric structure 77. A deformableelement containing an ionically conducting liquid may hereafter bereferred to as a deformable liquid element. A deformable elementcontaining an ionically conducting gel may hereafter be referred to as adeformable gel element. Such deformable elements may be deformed withrespect to electrical resistance by elongation, shortening, dilation,narrowing, electrode shading, etc. A plurality of electrical terminals81 a, 81 b, 81 c, 82 a, 82 b, and 82 c may provide for connection ofappropriate electrical circuitry for measurement of electricalresistance along various axes. Upper electrical terminals 81 a, 81 b,and 81 c are preferably equally spaced 120 degrees apart and arepreferably angularly offset from lower electrical terminals 82 a, 2 b,and 82 c, which are also equally spaced 120 degrees apart. The outer rimof elastomeric structure 77 may be radially stiffened by insert 78. Acover 80 may be used to shield electrical terminals 81 a, 81 b, and 81c. Retainer 79 may be used to fix elastomeric structure 77 to pedestal63.

Referring now to FIGS. 21 a through 21 f various views are shown ofanother embodiment of this invention wherein a plurality of discreteelastomeric elements such as lengths of rubber hose 83 each containingelectrolyte are provided. Hose clamps 84 may secure electrodes 81 and82. Mounting platforms 85 and 86 position the various electrodes 81 and82 and may transmit various applied forces thereto. Any deflection ofplatforms 85 and 86 relative to each other may cause a unique pattern ofelectrical resistance between the various electrical terminals 81 and82. Elongation of any of the various elastomeric elements 83 may resultin a longer distance between electrodes and a narrower cross section ofelectrolyte and thus a higher resistance. Measurement of saidresistances may be preferably done with an excitation signal ofalternating polarity in conjunction with standard am detectioncircuitry.

Referring now to FIG. 22, a cross section is shown cut along a hexagonalpath of yet another embodiment of the present invention. Various stagesof manufacture and assembly are indicated as follows: Elastomericstructure 87 may be molded with pins 88 in place. Pins 88 may bewithdrawn leaving cavities 89. Electrodes 90 may be inserted into thebottom of elastomeric structure 87. Cavities 89 may then be filled withelectrolyte 92. Upper electrodes 93 may then be inserted, sealing offelectrolyte 92 within cavities 89. Electrical connections 94 maycomplete the assembly of the sensing element portion of this embodimentof this invention.

Referring now to FIG. 23, two out of six sensing element assemblies aredepicted in a configuration that may provide for greater sensitivitythan is provided by the embodiment of FIG. 22. The nominal distancebetween upper electrodes 95 and lower electrodes 96 is small compared tothe height of elastomeric structure 87, resulting in a greater relativechange in electrode spacing for a given deflection of elastomericstructure 87.

Referring now to FIG. 24, an embodiment is depicted which may requireinsertion of only a single electrode assembly 97 into each cavity withinelastomeric structure 87. This embodiment may be simpler to manufactureand may be less affected by small amounts of air entrained within thecavities during assembly.

Referring now to FIGS. 25 a, 25 b, and 25 c, another embodiment of thepresent invention is shown wherein a deformable elastomeric structure100 may contain a plurality of internal stiffening elements 99 which maycouple strains of elastomeric structure 100 along selected axes tostrains which are more easily measured by a compact device 98 such as anarray of printed circuit board strain gauges or one or more MEMS forcesensors.

Referring now to FIG. 26, a partial view of another embodiment of thepresent invention is shown wherein stiffening elements 99 may be coupledto pressure sensing means 101 through fluid filled channels 102.

Referring to FIG. 27, a cross section of another embodiment of thepresent invention is shown wherein a deformable elastomeric structure 77may be provided to which displacement measurement devices 103 may bepivotably attached at locations 104 within a common cavity 105.Stiffening insert 78 may provide radial stiffness to the outer rim ofelastomeric structure 77. Preferably, six measurement devices 103 areprovided in the geometry of a Stewart platform.

Referring now to FIG. 28, a partial cross section of another embodimentof the present invention is shown wherein displacement measuring devices103 are fitted within discrete cavities 106 within elastomeric structure100.

Referring now to FIG. 29, a partial cross section view is showndepicting another embodiment of the present invention whereindisplacement measuring devices such as variable inductors ordifferential transformers are installed within individual cavitieswithin a deformable elastomeric structure. The embodiment shown furthermay provide for use of a single molded spherical seat 104 for eachindividual transducer 103. The partial cross section view of FIG. 29depicts two of the preferred quantity of six transducers 103 which maybe preferably oriented in a Stewart Platform configuration. Sphericalportion 106 of transducer assembly 103 may be seated in molded sphericalseat 104 within elastomeric body 100. Transformer cores 105 may featurespherical outside diameters which may slide within coil assemblies 106.Rod portions 107 connect spherical portions 106 with transformer cores105.

Referring now to FIG. 30, coil springs 108 within elastomeric structure100 may vary in inductance as they change length with deformation ofelastomeric structure 100. Variance in inductance may be measured inorder to establish an electronic representation of the deformed shape ofelastomeric structure 100.

Referring to FIG. 31, elastomeric structure 100 may feature inflatablecavities 89 within coils or coil springs 108. Inflatable cavities 89 maybe connected to an external source of compressed fluid or gas by meansof fittings 109 and hoses 110. Inflatable cavities 89 may be preferablyprovided in quantity six in a Stewart Platform configuration withinelastomeric structure 100. By way of this embodiment a force feedback or“haptic” joystick may be constructed. A combination of six of the twoelements shown may be termed a “stage” of an actuator. By mountingmultiple independently operable “stages” end-on-end, a robotic,snake-like device may be constructed with great flexibility andcontrollability. Such a multi-stage device may be useful for cathetersteering for medical applications, for example. Control of such multiplestage devices may preferably be by means of single pressure manifolds inconjunction with miniature valve manifolds such as MEMS valve assembliesthat are preferably addressed and actuated from a single digital databus. In this manner, a single compressed air line in conjunction with asingle data bus could be collocated along the center of an extendedmulti-stage actuator in a structure analogous to an vertebrate animalspine.

Referring now to FIGS. 32 a through 32 d, another embodiment of thepresent invention is shown wherein an electrolyte filled elastomericsensing element 77 (similar to that shown in FIGS. 20 a and 20 b) isused in combination with a gel filled wrist rest 111 and a numerickey-pad 112. The axis of symmetry of elastomeric sensing element 77 maybe inclined from vertical to allow the user's hand to be in acomfortable and relaxed position. The bottom 64 a of base portion 64could normally sit flat on a horizontal surface such as a desk.

Referring now to FIG. 33, yet another embodiment of the presentinvention is shown wherein left half 113 of game controller 116 may beconnected to the right half 114 of game controller 116 by means ofmulti-axis sensing element 115. By means of this embodiment, all of theconventional features of a two handed game controller may be preservedwhile six, for example, additional degrees of freedom may be added.

Referring now to FIG. 34, a wrist mounted embodiment of the presentinvention is depicted wherein hand strap 117 and wrist strap 118 maysecure base portion 119 to the user's hand 120. Active grip 1 may beconnected to base portion 119 through sensor portion 121.

Referring now to FIGS. 35 a through 35 g, 36 a and 36 b, photographs ofa model of another embodiment of the present invention are shown wherebytwelve degrees of freedom may be readily controlled with one hand.Fingertip operated grip 122 is connected by sensor means 121 (not shown)to hand held grip 123. The fingertip operated grip 122 may be preferablyapproximately 1 to ½ inches in diameter, a possibly novel level ofcompactness which the sensor means disclosed by this invention mayfacilitate. Additional sensor means for measurement of hand held gripinputs may be located within hand held grip 123 or at the base ofconnecting link 124, or within connecting link 124 or may be achieved byexternal, e.g., video measurement means.

Referring now to FIG. 37 a, 37 b, 38 a, 38 b, 38 c, and 38 d,photographs are shown depicting yet another embodiment of the presentinvention wherein a hand held stationary grip 125 may be used tostabilize the user's hand while active grip 122 may be operated inmultiple degrees of freedom, six for example, by the user's thumb,forefinger, and middle finger.

Referring now to FIG. 39, an example of one of many alternativeelectrical schematics for one class of embodiments of the presentinvention is shown.

Referring to FIG. 40 a, a perspective view is shown of an elastomericsensing element in accordance with one of the embodiments of thisinvention.

Referring now to FIG. 40 b, a cross sectional view is shown of thesensing element of FIG. 40 a.

Referring now to FIG. 41, an elevation view is shown of an embodiment ofthe present invention that incorporates a plurality of electricallyconductive elastomeric tensile members.

Referring now to FIG. 42, one of many possible representative electricalschematics is shown of one class of embodiments of the presentinvention.

Referring now to FIG. 43, one of many possible representative electricalschematics is shown of another embodiment of the present invention.

Referring now to FIG. 44, an example schematic is shown of anelectrolyte filled cavity of Stewart Platform geometry within adeformable elastomeric sensing element in accordance with one embodimentof the present invention.

Referring now to FIG. 45, a representative electrical schematic is showncorresponding to the embodiment of FIG. 44.

Referring now to FIG. 46, a cross section is shown of an embodiment ofthe present invention similar to the embodiment shown in FIGS. 15 athrough 15 e.

Referring now to FIG. 47, an example electrical signal scheme is shownwherein a three phase excitation Voltage represented by Voltages A, B,and C is applied to one set of terminals such as 61 a, 61 b, and 61 c ofthe embodiment of FIGS. 15 a through 15 e. Six degree of freedomposition information may be obtained, for example, by measurement of theVoltage and phase angle of Voltages D, E, and F as would be availablefor measurement at terminals 62 a, 62 b, and 62 c in the embodiment ofFIGS. 15 a through 15 e.

Referring to FIG. 48, a printed circuit board is shown which might beused in conjunction with the embodiment of FIG. 46.

Referring now to FIGS. 49 a, 49 b, 49 c, and 49 d, a joystick is shownwhich features a base 64 to which is mounted a gel pad wrist rest 111which allows the user comfortably clamp the base 64 securely against asupporting surface 126 such as a desk during manipulation of thejoystick. Pedestal 63 is attached to base 64 and may be shaped toprevent excessive rotation or horizontal movement of lower grip portion1 b. Lower grip portion 1 b is accordingly shaped to allow desirable butnot excessive movement about pedestal 63. The movement of lower gripportion 1 b is limited in the downward direction by base 64 and islimited in the upward direction by pedestal 63. Diaphragm 2 isconvoluted along several directions to provide flexibility in sixdegrees of freedom and provides protection of the optical componentsfrom dust and insects. Spring 10 provides a restoring force to the grip1 a and 1 b and also locates by way of holes 10 a and 10 b the uppergrip relative to the photo emitters 4 and photo detectors 5. Lower grip1 b is also located relative to pedestal 63 by means of spring 10.Spring 10 is depicted with three way symmetry.

Spring 10 may have any number of configurations such as two way symmetryor it may be constructed with a single spiral element. Upper grip 1 afeatures an internal surface with a combination of absorptive zones 1 cand reflective zones 1 d. Emitters 4 may be aimed directly at theboundaries betweens zones 1 c and zones 1 d. Photo detectors 5 may havea wide field of view and may each be responsive to the reflected lightfrom several photo emitters. If the photo emitters are energized one ata time, all of the photo detectors, photo diodes for example, may beelectrically connected in parallel and may be connected to a singleanalog input channel of a mixed signal integrated circuit such as aMicrochip PIC® device. Such a device may be mounted directly to circuitboard 13 along with other electronic components which may be required todirect power to the photo emitters 4 and to derive a signal from thephoto detectors 5. Upper grip 1 a as shown in FIGS. 49 a, 49 b, 49 c and49 d is drawn in this example at 53 mm diameter.

Referring now to FIGS. 50 a and 50 b, an embodiment of the presentinvention is shown which incorporates a monolithic photo transducer 44.Pedestal 63 is attached to base 64 and may be shaped to preventexcessive rotation or horizontal movement of lower grip portion 1 b.Lower grip portion 1 b is accordingly shaped to allow desirable but notexcessive movement about pedestal 63. The movement of lower grip portion1 b is limited in the downward direction by base 64 and is limited inthe upward direction by pedestal 63. Diaphragm 2 is convoluted alongseveral directions to provide flexibility in six degrees of freedom andprovides protection of the optical components from dust and insects.Spring 10 provides a restoring force to the grip 1 a and 1 b and alsolocates by way of holes 10 a and 10 b the upper grip relative to thephoto emitters 4 and photo detectors 5. Lower grip 1 b is also locatedrelative to pedestal 63 by means of spring 10. Spring 10 is depictedwith three way symmetry. Spring 10 may have any number of configurationssuch as two way symmetry or it may be constructed with a single spiralelement. Upper grip 1 a features an internal surface with a combinationof absorptive zones 1 c and reflective zones 1 d. Emitters 44 c may beaimed directly at the boundaries betweens zones 1 c and zones 1 d. Photodetectors 44 b may have a wide field of view and may each be responsiveto the reflected light from several photo emitters. FIGS. 50 a, 50 b,and 50 c are drawn to a scale such that upper grip 1 a is approximately40 mm in diameter, thus rendering it operable with the user's thumb tip,index finger tip, and middle finger tip and leaving the users remainingfingers available to grip a further device such as a mouse or joystickto which base 64 may be attached.

Referring now to FIG. 50 c, the monolithic optical transducer 44 ofFIGS. 50 a and 50 b is shown. Monolithic optical transducer 44 iscomprised of a substrate 44 e which may be a printed circuit board. sixdiscrete photo emitters 44 c and six discrete photo detectors 44 b mayeach be encased in a transparent medium such as epoxy resin. An opaquemedium may surround the transparent medium in order to prevent directtransmission of light between the photo emitters and photo detectors. Areflective coating 44 j may be applied to the outer surface of thetransparent medium 44 h prior to over-molding for example with opaquemedium 44 i. Connection pins 44 a provide power to and transmit datafrom the device by means of a an interface such as USB for example.Mixed signal microcontroller 44 d and other electronic components as maybe required may be mounted to substrate 44 e and encapsulated is resinsystems 44 h and/or 44 i. In this manner a low cost robust transducerpackage may be produced.

Referring now to FIGS. 51 a, 51 b, 51 c, 51 d, 51 e, 51 f, and 51 g, anembodiment of the present invention is shown wherein a six axis joystick1 as attached to a three axis mouse 64 a. The mouse is shaped to allowthe users wrist to be substantially vertical thus permitting greaterrange of z axis rotation of the mouse base. The depicted shape alsofacilitates firm grasping of the mouse portion against the user's palmby the user's ring finger and little finger. A ridge between the userspalm and bent fingers further enhances security of gripping. Thejoystick is approximately 40 mm in diameter and thus allows easymanipulation with the user's thumb, index finger and middle finger. Thebottom surface of the mouse features two sets of offset conventionaloptical mouse transducers. Each transducer set may measure both x and ymovements, although the transducer set at one of the two locations needonly measure x movements. For nomenclature purposes, the transducer setslie along a line parallel to the y axis. The third mouse axis is derivedfrom z axis twisting of the mouse which causes a differential output ofthe two x transducers. The depicted device provides 9 degrees offreedom. buttons may also be provided around the periphery of the baseof the six axis joystick. A small ten key pad may be added to the top ofthe device.

Referring now to FIG. 52, another embodiment of the present invention isshown wherein a joystick 1 controls a hexapod adaptor 126 which controlsthe spatial relationship between a piece of construction equipment 131,in this case a loader, and a removable implement 133 , in this case abucket. Various other implements such as forks, grapples, booms, saws,hammers, augers, drills, mowers, etc. may be similarly controlled.Machine vision sensor 130 which may be a video camera is used to machinedetermine the posture of the linkage 127 relative to the joystick 1. Themachine vision sensor 130 may also be used to sense the posture of thehexapod 126. The posture of hexapod stage 126 may also be interpreted bymachine vision means such as by video camera or scanning laser beam.Such a laser beam might, for example scan reflective tags on each of thesix struts. The timing of the reflected signals might be used todetermine the posture of the hexapod. Various other machine visionschemes could also be used. Alternatively or conjunctively postureinformation may be deduced from discrete sensors such as MEMS (MicroMechanical Electrical Systems) devices 126 c attached to attached to thehexapod struts and MEMS devices 126 b and 126 d attached to platforms128 and 132. Further MEMS devices (which may be accelerometers orangular rate sensors for example) 127 a and 129 a may be attached to thevarious parts of the linkage 127 of a machine. Such devices may beattached magnetically and preferably transmit information wirelessly.

Exhibit A illustrates a general approach to determining the position,angular velocity, and angular acceleration of a machine element on thebasis of MEMS accelerometer data. A similar approach may be used todetermine the position, angular velocity, and angular acceleration ofmultiple connected linkages such as robotic arms, hexapods, combinationsthereof and the like.

Referring now to FIG. 53, a partial general control arrangement is shownwhich might be used in conjunction with the embodiment shown in FIG. 52.Joystick 1 is used by the operator to control slave platform 132.Coordinates are continuously adjusted to match the user's frame ofreference by computer 139 using machine vision sensor 130 and/ordiscrete sensors 127 a, 127 b, 126 c, 126 d, and the like. Conventionalabsolute angle and position encoders may also be utilized. Hexapodstruts 126 may be hydraulically controlled by hydraulic valve manifold137, which may receive electrical power through motion controller 134from hydraulic electrical generator 136. Hydraulic electrical generator136 may also supply electrical power to transceiver 135. Transceiver 135may receive motion command data from transceiver 138. Such a scheme isadaptable to a wide variety of machinery. Installation of such equipmentneed not be permanent and may be well suited even to rental constructionequipment. In general, the accuracy of the posture determining systemneed only be sufficient to reasonably align the hexapod, for example,frame of reference with the frame of reference of the operator. Absoluteposition feedback would be in direct visual or audible directly to theoperator, independent of the control system. Optionally, a hapticjoystick could be utilized to provided tactile force feedback.

As can be easily understood from the foregoing, the basic concepts ofthe present invention may be embodied in a variety of ways. It involvesboth multi-axis input techniques as well as devices to accomplish theappropriate method. In this application, the multi-axis input techniquesare disclosed as part of the results shown to be achieved by the variousdevices described and as steps which are inherent to utilization. Theyare simply the natural result of utilizing the devices as intended anddescribed. In addition, while some devices are disclosed, it should beunderstood that these not only accomplish certain methods but also canbe varied in a number of ways. Importantly, as to all of the foregoing,all of these facets should be understood to be encompassed by thisdisclosure.

The discussion included in this application is intended to serve as abasic description. The reader should be aware that the specificdiscussion may not explicitly describe all embodiments possible; manyalternatives are implicit. It also may not fully explain the genericnature of the invention and may not explicitly show how each feature orelement can actually be representative of a broader function or of agreat variety of alternative or equivalent elements. Again, these areimplicitly included in this disclosure. Where the invention is describedin device-oriented terminology, each element of the device implicitlyperforms a function. Not only are apparatus claims included for thedevice described, but also method or process claims may be included toaddress the functions the invention and each element performs. Neitherthe description nor the terminology is intended to limit the scope ofthe claims which will be included in a full patent application.

It should also be understood that a variety of changes may be madewithout departing from the essence of the invention. Such changes arealso implicitly included in the description. They still fall within thescope of this invention. A broad disclosure encompassing both theexplicit embodiment(s) shown, the great variety of implicit alternativeembodiments, and the broad methods or processes and the like areencompassed by this disclosure and may be relied upon for support of theclaims for the full patent application. It should be understood thatsuch language changes and broad claiming is accomplished in thisapplication based on a provisional filing. This patent application mayseek examination of as broad a base of claims as deemed within theapplicant's right and is designed to yield a patent covering numerousaspects of the invention both independently and as an overall system.

Further, each of the various elements of the invention and claims mayalso be achieved in a variety of manners. This disclosure should beunderstood to encompass each such variation, be it a variation of anembodiment of any apparatus embodiment, a method or process embodiment,or even merely a variation of any element of these. Particularly, itshould be understood that as the disclosure relates to elements of theinvention, the words for each element may be expressed by equivalentapparatus terms or method terms—even if only the function or result isthe same. Such equivalent, broader, or even more generic terms should beconsidered to be encompassed in the description of each element oraction. Such terms can be substituted where desired to make explicit theimplicitly broad coverage to which this invention is entitled. As butone example, it should be understood that all actions may be expressedas a means for taking that action or as an element which causes thataction. Similarly, each physical element disclosed should be understoodto encompass a disclosure of the action which that physical elementfacilitates. Regarding this last aspect, as but one example, thedisclosure of a “means for detecting” or a “detector” should beunderstood to encompass disclosure of the act of “detecting”—whetherexplicitly discussed or not—and, conversely, were there effectivelydisclosure of the act of “detecting”, such a disclosure should beunderstood to encompass disclosure of a “detector” and even a “means fordetecting”. Such changes and alternative terms are to be understood tobe explicitly included in the description.

Patents, publications, or other references mentioned in this applicationfor patent are hereby incorporated by reference. In addition, as to eachterm used it should be understood that unless its utilization in thisapplication is inconsistent with such interpretation, both traditionaland common dictionary definitions should be understood as incorporatedfor each term and all definitions, alternative terms, and synonyms suchas contained in the Random House Webster's Unabridged Dictionary, secondedition are hereby incorporated by reference. Finally, all referenceslisted in the list of References To Be Incorporated By Reference InAccordance With The Patent Application or other information statement orlist of references filed with the application are hereby appended andhereby incorporated by reference, however, as to each of the above, tothe extent that such information or statements incorporated by referencemight be considered inconsistent with the patenting of this inventionsuch statements are expressly not to be considered as made by theapplicants.

Thus, the applicants should be understood to claim at least: i) each ofthe input devices as herein disclosed and described, ii) the relatedmethods disclosed and described, iii) similar, equivalent, and evenimplicit variations of each of these devices and methods, iv) thosealternative designs which accomplish each of the functions shown as aredisclosed and described, v) those alternative designs and methods whichaccomplish each of the functions shown as are implicit to accomplishthat which is disclosed and described, vi) each feature, component, andstep shown as separate and independent inventions, vii) the applicationsenhanced by the various systems or components disclosed, viii) theresulting products produced by such systems or components, ix) methodsand apparatuses substantially as described hereinbefore and withreference to any of the accompanying examples, x) the variouscombinations and permutations of each of the elements disclosed, xi)each potentially dependent claim or concept as a dependency on each andevery one of the independent claims or concepts presented, xii)processes performed with the aid of or on a computer as describedthroughout the above discussion, xiii) a programmable apparatus asdescribed throughout the above discussion, xiv) a computer readablememory encoded with data to direct a computer comprising means orelements which function as described throughout the above discussion,xv) a computer configured as herein disclosed and described, xvi)individual or combined subroutines and programs as herein disclosed anddescribed, xvii) the related methods disclosed and described, xviii)similar, equivalent, and even implicit variations of each of thesesystems and methods, xix) those alternative designs which accomplisheach of the functions shown as are disclosed and described, xx) thosealternative designs and methods which accomplish each of the functionsshown as are implicit to accomplish that which is disclosed anddescribed, xxi) each feature, component, and step shown as separate andindependent inventions, and xxii) the various combinations andpermutations of each of the above.

It should also be understood that for practical reasons and so as toavoid adding potentially hundreds of claims, the applicant mayeventually present claims with initial dependencies only. Support shouldbe understood to exist to the degree required under new matterlaws—including but not limited to European Patent Convention Article123(2) and United States Patent Law 35 USC 132 or other such laws—topermit the addition of any of the various dependencies or other elementspresented under one independent claim or concept as dependencies orelements under any other independent claim or concept. Further, if orwhen used, the use of the transitional phrase “comprising” is and willbe used to maintain the “open-end” claims herein, according totraditional claim interpretation. Thus, unless the context requiresotherwise, it should be understood that the term “comprise” orvariations such as “comprises” or “comprising”, are intended to implythe inclusion of a stated element or step or group of elements or stepsbut not the exclusion of any other element or step or group of elementsor steps. Such terms should be interpreted in their most expansive formso as to afford the applicant the broadest coverage legally permissible.

Any claims set forth at any time are hereby incorporated by reference aspart of this description of the invention, and the applicant expresslyreserves the right to use all of or a portion of such incorporatedcontent of such claims as additional description to support any of orall of the claims or any element or component thereof, and the applicantfurther expressly reserves the right to move any portion of or all ofthe incorporated content of such claims or any element or componentthereof from the description into the claims or vice-versa as necessaryto define the matter for which protection is sought by this applicationor by any subsequent continuation, division, or continuation-in-partapplication thereof, or to obtain any benefit of, reduction in feespursuant to, or to comply with the patent laws, rules, or regulations ofany country or treaty, and such content incorporated by reference shallsurvive during the entire pendency of this application including anysubsequent continuation, division, or continuation-in-part applicationthereof or any reissue or extension thereon.

(1) 1-D accelerometer at each point, A and B, both oriented parallel toradius and away from center. X-axis taken along moving element, y-axisperpendicular to element as shown. (1) 1-D accelerometer parallel toy-axis and fixed at A.

Accelerations at each point:

${\overset{arrow}{a}}_{A} = ( {{g_{x} + {\overset{¨}{\theta} \cdot r_{A}}},{g_{y} + \frac{V_{A}^{2}}{r_{A}}}} )$

${\overset{arrow}{a}}_{B} = ( {{g_{x} + {\overset{¨}{\theta} \cdot r_{B}}},{g_{y} + \frac{V_{B}^{2}}{r_{B}}}} )$where

$\frac{V_{A}^{2}}{r_{A}}$and

$\frac{V_{B}^{2}}{r_{B}}$are tangential velocities. | g|={square root over (g_(x) ²+g_(y) ²)}, sofinding g_(y) gives: g_(x)={square root over (g²−g_(y) ²)}thus:

$\theta = {{\arctan( \frac{g_{y}}{g_{x}} )} = {\arctan( \frac{g_{y}}{\sqrt{g^{2} - g_{y}^{2}}} )}}$

Since V_(A)=r_(A)·{dot over (θ)} and V_(B)=r_(B)·{dot over (θ)}, we maywrite:

$a_{A,y} = {( {g_{y} + \frac{( {r_{A} \cdot \overset{.}{\theta}} )^{2}}{r_{A}}} ) = {g_{y} + {r_{A} \cdot {\overset{.}{\theta}}^{2}}}}$

$a_{B,y} = {( {g_{y} + \frac{( {r_{B} \cdot \overset{.}{\theta}} )^{2}}{r_{B}}} ) = {g_{y} + {r_{B} \cdot {\overset{.}{\theta}}^{2}}}}$

$ \Rightarrow{( {g_{y} + {r_{1} \cdot {\overset{.}{\theta}}^{2}}} ) - {\frac{r_{A}}{r_{B}}( {g_{y} + {r_{2} \cdot {\overset{.}{\theta}}^{2}}} )}}  = {( {1 - \frac{r_{1}}{r_{2}}} )g_{y}}$So:

$g_{y} = { \frac{a_{A,y} - {\frac{r_{A}}{r_{B}}a_{B,y}}}{1 - \frac{r_{A}}{r_{B}}}\Rightarrow\theta  = {\arctan( \frac{\frac{a_{A,y} - {\frac{r_{A}}{r_{B}}a_{B,y}}}{1 - \frac{r_{A}}{r_{B}}}}{\sqrt{g^{2} - ( \frac{a_{A,y} - {\frac{r_{A}}{r_{B}}a_{B,y}}}{1 - \frac{r_{A}}{r_{B}}} )^{2}}} )}}$

$\overset{.}{\theta} = {\sqrt{\frac{a_{A,y} - g_{y}}{r_{A}}} = \sqrt{\frac{a_{B,y} - g_{y}}{r_{B}}}}$

$\overset{¨}{\theta} = {\frac{a_{A,x} - g_{x}}{r_{A}} = \frac{a_{A,x} - \sqrt{g^{2} - \lbrack \frac{a_{A,y} - {\frac{r_{A}}{r_{B}}a_{B,y}}}{1 - \frac{r_{A}}{r_{B}}} \rbrack^{2}}}{r_{A}}}$Alternatively:

$\overset{¨}{\theta} = \frac{a_{A,x} - a_{B,x}}{( {r_{A} - r_{B}} )}$

1. A joystick comprising: at least two elements movable with respect toeach other in at least six degrees of freedom wherein six elastomeric,ionically conductive elements are utilized to generate a position signalof at least three degrees of freedom, each of said six elastomeric,ionically conductive elements having an upper end and a lower end; andan upper circuit board above said six elastomeric, ionically conductiveelements and a lower circuit board below said six elastomeric, ionicallyconductive elements, said upper circuit board comprising an upper halfof said electrical terminals and said lower circuit board comprising alower half of said electrical terminals, wherein each of said upper halfof said electrical terminals are connected with an upper end of one ofsaid elastomeric, ionically conductive elements, and each of said lowerhalf of said electrical terminals are connected with a lower end of oneof said elastomeric, ionically conductive elements wherein said upperhalf of said electrical terminals are angularly spaced one hundredtwenty degrees apart and said lower half of said electrical terminalsare angularly spaced one hundred twenty degrees apart, wherein saidupper half of said electrical terminals are angularly offset sixtydegrees from said lower half of said electrical terminals, wherein saidelastomeric, ionically conductive elements, said electrical terminalsand said circuit boards form at least part of a variable resistancecircuit, and wherein said variable resistance circuit has a shapeanalogous to Stewart platform actuator geometry.
 2. A joystick asdescribed in claim 1 further comprising a pedestal established belowsaid lower circuit board.
 3. A joystick as described in claim 1 whereinone of said elements movable with respect to each other comprises agrip.
 4. A joystick as described in claim 1 wherein said elastomeric,ionically conductive elements comprise a metal salt dissolved in apolymer solid solution.
 5. A joystick as described in claim 1 whereinsaid elastomeric, ionically conductive elements comprise an elastomericmaterial selected from the group consisting of an intrinsicallyconductive polymer, and a polymer with a conductive filler.
 6. Ajoystick as described in claim 1 wherein an electrical signal passingthrough said elastomeric, ionically conductive elements is ofalternating polarity.
 7. A joystick as described in claim 1 wherein saidelastomeric, ionically conductive elements comprise cavities containingan electrolyte.
 8. A joystick as described in claim 7 wherein saidelectrolyte comprises an electrolyte selected from the group consistingof: an electrically conducting liquid and an electrically conductinggel.